Abstract: Based on the system analysis, a mathematical model is established for the oil product pipeline. In the model, the minimum total discounted cost during the whole life of the pipeline is taken as the optimal criterion. The tatal cost includes initial investment, discounted operation and maintenance costs and discounted power costs. This model is a complex of nonlinear programming and integer programming. The decision parameters are pipeline material, diameter, and outlet pressure; the constraints are hydraulic constraints, strength constraints, pump station performance constraints, and line pipe specification constraints.