Abstract: The hydraulic calculation in the design of urban gas pipeline network is a very important work. The traditional calculation method used before, for example, the integral square error, has disadvantages, such as long period, larger error and conservative. A new hydraulic calculation software for urban gas pipeline network is developed with Visual Basic 5.0, in which the lineal shrinkage at juncture is adopted. Some calculation cases are given. The calculation speed is greatly improved with a high accuracy and satisfactory results.