EN日本語

Keio line4 min read

Keio Line

京王線

The Keiō Line is a 37.9-kilometre railway line in western Tokyo, Japan, owned and operated by the private railway operator Keio Corporation. It runs westward from Shinjuku, in the heart of Tokyo, to Keiō-Hachiōji in the suburban city of Hachiōji.

Counting the two termini, it has 34 stations, although two of them near the Tokyo end, Hatsudai and Hatagaya, are reachable only via the parallel Keiō New Line rather than the Keiō Line proper.

The route follows the Kōshū Kaidō highway, passing through the northern parts of Shibuya and Setagaya wards (at times crossing into Suginami), then crossing the Tama area through the cities of Chōfu, Fuchū, Tama and Hino before reaching Hachiōji, the most populous city in the Tama region. The line is electrified at 1,500 V DC by overhead line, uses an unusual track gauge of 1,372 mm, is protected by Keio's ATC cab-signalling system, and has a maximum operating speed of 110 km/h (105 km/h east of Chōfu). The name 'Keiō' (京王), shared by the line and the company, joins the second character of Tōkyō (東京) with the second character of Hachiōji (八王子).

TokyoTamaAsaoTamaKodairaMitakaTakatsu10 km
Route of the Keio Line · Tokyo · Boundaries: MLIT / GSI / Japan Post
Keio 5000 series formation 5737 on a Keio Liner service, passing through Sakurajosui Station on the Keio Line.
Keio 5000 series formation 5737 on a Keio Liner service, passing through Sakurajosui Station on the Keio Line. · MaedaAkihiko · CC BY-SA 4.0 · Wikimedia Commons

History

The line began as an interurban electric railway. The Keiō Electric Tramway opened the Sasazuka–Chōfu section on 15 April 1913, with the Yoyohata–Sasazuka section (1.3 km) following on 11 October 1913. It extended in short stages in both directions, through-connecting the original Shinjuku-Oiwake terminus to Fuchū in 1916. Until the gaps closed, the company ran connecting buses between Shinjuku and Sasazuka and between Chōfu, Fuchū and Kokubunji; Keio's own company history records this as the first bus service in Tokyo. The line was laid along the Kōshū Kaidō, linking the highway's former post towns from Naitō-Shinjuku through Takaido and the five Fuda post towns to Fuchū. The competing government Chūō Main Line, opened by the Kōbu Railway in 1889 and nationalised in 1906, ran a straighter course across the Musashino Plateau well to the north.

The extension beyond Fuchū was built by a related company, the Gyokunan Electric Railway, which opened the Fuchū–Higashi-Hachiōji section (16.3 km; Higashi-Hachiōji is today's Keiō-Hachiōji) on 24 March 1925. To qualify for a government subsidy, Gyokunan built this stretch as a railway under the Local Railway Act rather than as a tramway, and to the Japanese standard narrow gauge of 1,067 mm, so the two companies' trains could not run through onto each other's tracks. The subsidy was refused on the grounds that the line competed with the Chūō Main Line. Keiō therefore absorbed Gyokunan on 1 December 1926, re-gauged the section to 1,372 mm (completed 1 June 1927), and began through operation between Shinjuku-Oiwake and Higashi-Hachiōji on 22 May 1928. Double-tracking came in stages. Sasazuka–Chōfu was doubled in 1920 and Chōfu–Fuchū in 1923; Fuchū–Nakagawara and Sekido (today's Seiseki-Sakuragaoka)–Kitano followed in 1929, and Nakagawara–Seiseki-Sakuragaoka on 21 April 1964. The last section, Kitano–Keiō-Hachiōji, was doubled in 1970, completing double track over the whole line. Under wartime consolidation the company was merged into Tokyo Kyuko Dentetsu (Tokyu) on 31 May 1944, and on 1 June 1948, when the 'Greater Tokyu' combine was broken up, the Keiō lines were spun off into the newly independent Keio Teito Electric Railway.

The Tokyo-end approaches were rebuilt from the 1960s onward; sections east of Hatagaya had originally been street-running track on the Kōshū Kaidō. In 1963 the Shinjuku underground station opened on 1 April, the overhead voltage was raised to 1,500 V DC on 4 August, and limited-express service began between Shinjuku and Higashi-Hachiōji on 1 October. On 11 December that year the western terminus, Higashi-Hachiōji, was moved about 120 m toward Shinjuku and renamed Keiō-Hachiōji. The Shinjuku–Sasazuka segment was quadruple-tracked on 31 October 1978 with the opening of the Keiō New Line, when Hatsudai and Hatagaya moved onto the new line; through-running with the Toei Shinjuku Subway Line began on 16 March 1980. Keiō-Hachiōji Station was put underground on 2 April 1989. West of Chōfu, the flat junction with the Keiō Sagamihara Line had long been a bottleneck for the whole network; the line around Chōfu was placed underground to remove it, and the Chōfu-to-Kokuryō underground section was completed in 2012.

Keio second-generation 5000 series at Shinjuku Station on the Keio Line. View full size (opens in a new tab)
Keio second-generation 5000 series at Shinjuku Station on the Keio Line.雑用部 · CC BY-SA 4.0 · Wikimedia Commons

The operator was renamed from Keio Teito Electric Railway to Keio Corporation on 1 July 1998. Today the Keiō Line forms part of an interconnected network with through services to the Keiō New Line, Sagamihara Line, Keibajō Line, Dōbutsuen Line and Takao Line, plus the separate 1,067 mm-gauge Inokashira Line. Six grades of limited-stop service run alongside local trains — Rapid, Semi Express, Express, Special Express, the reserved-seat Mt. TAKAO service on weekends and holidays, and the Keiō Liner, a reserved-seat, supplementary-fare service introduced on 22 February 2018 linking Shinjuku with Keiō-Hachiōji and with Hashimoto on the Sagamihara Line. Through services onto the Takao Line carry sightseers and hikers to Mount Takao, which draws more climbers than any other mountain in Japan, while services onto the Sagamihara Line link central Tokyo with Tama New Town and Sagamihara.

The Keiō Line is heavily used and notably congested. Its daily ridership in 2010 was 1,349,238, and Keio's Shinjuku Station handles a daily average of over 700,000 users — second among private-railway terminals after Tokyu's Shibuya. In fiscal 2024 the most congested section was Shimo-Takaido to Meidaimae, with a congestion rate of 143 percent in the morning peak hour (7:40–8:40). The line is also known for its level crossings: the 25 on the 7.2 km between Sasazuka and Sengawa are classified by the Tokyo Metropolitan Government Construction Bureau as 'akazu no fumikiri' ('crossings that never open') because they are shut to road traffic for more than 40 minutes in an hour. A continuous grade-separation project to elevate that section is under way, its authorisation period extended by a national notice of 15 March 2022 to the end of fiscal 2030.

Stations on this line

34 stations tracked on the map, listed alphabetically. Select any to read its page.

Timeline
  • 191315 April: the Keiō Electric Tramway opens the Sasazuka–Chōfu section; the Yoyohata–Sasazuka section (1.3 km) follows on 11 October.
  • 1916The route from the Shinjuku-Oiwake terminus to Fuchū is through-connected; connecting buses had bridged the unfinished gaps.
  • 192524 March: the related Gyokunan Electric Railway opens the Fuchū–Higashi-Hachiōji section (16.3 km), built to 1,067 mm gauge as a Local Railway Act line to seek a government subsidy.
  • 19261 December: after the subsidy is refused (competition with the Chūō Main Line), Keiō merges Gyokunan.
  • 19271 June: re-gauging of the Fuchū–Higashi-Hachiōji section from 1,067 mm to 1,372 mm is completed.
  • 192822 May: through operation begins between Shinjuku-Oiwake and Higashi-Hachiōji.
  • 1929The Fuchū–Nakagawara and Seiseki-Sakuragaoka–Kitano sections are double-tracked.
  • 194431 May: under wartime transport consolidation the company is merged into Tokyo Kyuko Dentetsu (Tokyu).
  • 19481 June: on the break-up of the 'Greater Tokyu' combine, the line passes to the newly independent Keio Teito Electric Railway.
  • 19631 April: the Shinjuku underground station opens. 4 August: overhead voltage is raised to 1,500 V DC. 1 October: limited-express service begins between Shinjuku and Higashi-Hachiōji. 11 December: the western terminus, Higashi-Hachiōji, is moved about 120 m toward Shinjuku and renamed Keiō-Hachiōji.
  • 196421 April: the Nakagawara–Seiseki-Sakuragaoka section is double-tracked.
  • 1970The Kitano–Keiō-Hachiōji section is double-tracked, completing double-tracking of the entire Keiō Line.
  • 197831 October: the Shinjuku–Sasazuka segment is quadruple-tracked with the opening of the Keiō New Line; Hatsudai and Hatagaya stations move onto the new line.
  • 198016 March: mutual through-running with the Toei Shinjuku Subway Line begins.
  • 19892 April: Keiō-Hachiōji Station is put underground.
  • 19981 July: the operator is renamed from Keio Teito Electric Railway to Keio Corporation.
  • 2012The underground section of the line from around Chōfu Station to Kokuryō is completed, removing the flat junction with the Sagamihara Line.
  • 201822 February: the reserved-seat, supplementary-fare Keiō Liner service is introduced (Shinjuku to Keiō-Hachiōji and Hashimoto).
  • 202215 March: a national notice extends the authorisation period of the Sasazuka–Sengawa continuous grade-separation project to the end of fiscal 2030.

Sources

Last updated 16 October 2026.

View on the map → ← All lines