Abstract: Suitable operating pressure is of vital importance to the safety of long distance gas pipeline. Determination of operating pressure of such pipeline should be abided by following principle: first, overall considering the upstream and downstream of pipeline when the pipeline system is failure; second, establishing the range of pipeline allowing operation pressure, third, determining the range of pipeline normal operation pressure and fourth, determining the range of control pressure for different positions. The maximum design operating pressure of Zhuhai-Zhongshan gas pipeline is 7.1 MPa. According to user's requirements, the minimum operating pressure is adjusted. During normal operation, the minimum operating pressure of pipeline is 4.5 MPa. When the upstream gas supply is interrupted, the minimum operating pressure is adjusted to 4.67 MPa; when the downstream gas supply to user is interrupted, the maximum operating pressure is adjusted to 6.3 MPa in accordance with the management and control. Meanwhile, influence factors such as typhoon, equipment failures etc. should be taken into account when determining the pipeline operating pressure.