The line runs from North Point on the Hong Kong Island to the new town of Tseung Kwan O.

It bifurcates east of Tseung Kwan O station into two branches, one northward to Po Lam and one southward to LOHAS Park.

The stations of Yau Tong, Po Lam and LOHAS Park are at ground level, but are completely shielded to minimise noise to the surrounding development.

From Yau Tong, the line passes through the Black Hill Tunnels to enter Tseung Kwan O New Town at Tiu Keng Leng.

LOHAS Park is a large residential development built above the Tseung Kwan O Depot, where the trains of the line are maintained.

Passengers travelling to and from LOHAS Park during non-peak hours are required to change trains at Tiu Keng Leng or Tseung Kwan O in order to continue their journey.

[8] MTR re-proposed the line in 1993, and the plan was approved by the Hong Kong Executive Council on 20 October 1998.

The K-Stock trains were manufactured by a consortium of Hyundai Rotem and Mitsubishi Corporation, and were expected to be quieter and to use energy generated from deceleration.