The , commonly called the Chà «à  Line, is one of the major trunk railway lines in Japan. It connects Tokyo and Nagoya, although it is the slowest direct railway connection between the two cities; the coastal Tà Âkaidà  Main Line is slightly faster, and the Tà Âkaidà  Shinkansen is currently the fastest rail link between the cities.
The eastern portion, the , is operated by the East Japan Railway Company (JR East), while the western portion, the , is operated by the Central Japan Railway Company (JR Central). The dividing point between the two companies is , where express trains from both operators continue north onto the Shinonoi Line towards the cities of Matsumoto and Nagano. Compared to the huge urban areas at either end of the Chà «à  Line, its central portion is lightly traveled; the Shiojiri-Nakatsugawa corridor is only served by one limited express and one local service per hour.
The Chà «à  Main Line passes through the mountainous center of Honshu. Its highest point (near ) is about above sea level and much of the line has a gradient of 25 per mil (2.5% or 1 in 40). Along the Chà «à  East Line section, peaks of the Akaishi and Kiso as well as Mount Yatsugatake can be seen from trains. The Chà «à  West Line parallels the old Nakasendà  highway (famous for the preserved post towns of Tsumago-juku and Magome-juku) and the steep Kiso Valley.
This section lists all stations on the Chà «à  Main Line and generally explains regional services on the line. In addition, there are limited express services connecting major cities along the line, namely Azusa, Super Azusa, Kaiji, Hamakaiji, Narita Express and Shinano. For details of the limited express trains, see the relevant articles.
The section between Tokyo and Mitaka is grade-separated, with no level crossings. Between Ochanomizu and Mitaka, the Chà «à  Main Line has four tracks; two of them are with platforms at every station; the other two are with some stations without platforms. The local tracks are used by the Chà «à Â-Sà Âbu Line local trains, while the rapid tracks carry rapid service and limited express trains. The Tokyo-Mitaka portion is a vital cross-city rail link.
The commuter services on the rapid tracks are collectively called the Chà «à  Line (Rapid) in comparison with the or the Chà «à Â-Sà Âbu Line on the local tracks. The former is usually referred to simply as the Chà «à  Line and the latter the Sà Âbu Line. Separate groups of trainsets are used for these two groups of services: cars with an orange belt for the rapid service trains and cars with a yellow belt for the local service trains. Signs at stations also use these colors to indicate the services.
This section is located entirely within Tokyo.
The four-track section ends at Mitaka. Most of the section between Mitaka and Tachikawa had been elevated between 2008 and 2011 to eliminate level crossings. Plans have been proposed to add another two tracks as far as Tachikawa, but were not included in the track elevation.
Most of the rapid service trains from Tokyo terminate at Takao, where the line exits the large urban area of Tokyo. The section between Takao and à Âtsuki still carries some commuter trains as well as long distance local trains and Limited Express trains. The Kaiji limited express terminates at Kà Âfu, the capital of Yamanashi Prefecture, while the Azusa continue beyond Shiojiri to Matsumoto via the Shinonoi Line.
All stations from Takao to Shiojiri are served by the Chà «à  Main Line Local. Local trains from Takao run as far as Matsumoto or even Nagano.
Legends:
Station numbers were introduced through Shiojiri in February 2025.
The Okaya-Shiojiri branch is an old route of the Chà «à  Main Line. It carries a small number of shuttle trains and trains from/to the Iida Line, which branches off at Tatsuno.
Prior to the opening of the new route between Okaya and Shiojiri, there was a junction () between and stations. It had a reversing layout. The signal station was closed on 12 October 1983.
Shiojiri is the dividing point of the East Line and the West Line; no train continues from one to the other. The Shinano limited express is the main service for the rural Shiojiri-Nakatsugawa section.
Local and rapid service trains run on the line from Nakatsugawa to Nagoya. This section carries urban traffic for the Greater Nagoya Area.
Local trains stop at all stations (except Sannà  Junction).
Legends:
New E233 series trains entered service on Tokyo-area commuter services from 26 December 2006. These trains are a development of the E231 series used on other commuter lines in the Tokyo area, and replaced the aging 201 series rolling stock introduced on the line in 1981.
From 2017, new E353 series EMUs were introduced on Azusa and Super Azusa limited express services, replacing the E351 and E257 series trains.
From 2021, E259 series EMUs on Narita Express services to and from Takao ceased operations.
The opened the initial section of the Chà «à  Line from Shinjuku Station to Tachikawa Station in 1889. The company then extended the line both westward and eastward (towards Tokyo) until it was nationalised in 1906. The Japanese Government Railways (JGR) then continued to extend the line, reaching Shiojiri the same year, and Tokyo (at ) in 1908. The JGR also built the line from Nagoya, the first section opening in 1900, with the lines connecting in 1911. The Table below gives the section opening dates.
In 1904, the section between Iidamachi Station (formerly located between Suidà Âbashi Station and Iidabashi Station) and Nakano Station was the first urban electric railway in Japan using 600 V DC. Electrification was extended in 1919 and 1922, was increased to 1,200 V DC when extended to Tokyo in 1927, boosted again to 1,500 V DC in 1929, and reached Kofu in 1931. Electrification from the Nagano end was commissioned in sections from 1966, and the entire line was electrified by 1973.
Notes:
On September 12, 1997, a Super Azusa limited express bound for Matsumoto collided with a 201 series local train that failed to stop at a red signal while passing through à Âtsuki Station.