The line is mostly double-track, except for 1.1 km (1200 yards) of single track between Wakita Junction and Hon-Kawagoe Station.

While the section from Seibu-Shinjuku to Takadanobaba is elevated, the line runs at ground level through a suburban area until Saginomiya.

In addition, operation of the all-seat reserved train "Haijima Liner" using the Seibu 40000 series EMU started from March of 2018.

This section was built by the Kawagoe Railway (川越鉄道, Kawagoe Tetsudō) to serve as a freight feeder for the Kōbu Railway (甲武鉄道, Kōbu Tetsudō) between Shinjuku and Tachikawa (now known as the Chūō Main Line).

This plan was later scrapped due to insufficient space to handle trains longer than six cars.

[7] From the timetable revision on 14 March 2020, the limited-stop Rapid Express (快速急行, Kaisoku Kyūkō) was reinstated for weekend and holiday services.

This plan was indefinitely postponed in 1995 due to costs and a decline in passenger ridership versus previous projections.

The transfer is considerably crowded during the rush hour, as Takadanobaba is the busiest station on the entire Seibu Shinjuku Line.