Abstract: A reasonable economic model for the all-round design optimization of gas pipeline is introduced, considering each factor having effect on the total investment of gas pipeline (pipe diameter, pipe wall thickness, compression ratio, gas pressure, investment's time value, etc.), and with the target functions being the costs by the end of equipments' service life. By means of this model, which maintains the preset terminal pressure, every target function can be calculated with the given parameters under basic assumed conditions. Option comparison shows that the model gives comprehensive indication about the effect of every factor on total cost. Wherever the case is applicable and parameters are defined, optimal valves can be obtained easily for all design variabless.