Abstract: The pipeline transportation of oil and gas is the development direction of the oil and gas transmission in the future. The optimum design of the oil and gas pipelines is the key procedure of the pipeline construetion, which will realize the purpose of reducing the design time and saving the investment by adopting various optimizing technologies in the design. The research work of the optimum design towards the oil and gas pipelines has been conducted since the 50-60's in the 20 century abroad and has achieved much progress. However, compared the abroad, this work was set about much later in China and also acquires certain advancement by consulting the foreign equivalent. The previous research did not consider the uncertainty of pipelines'annual transportation capacity after their operation, and the pipeline scheme that follows the deterministic transportation capacity design differs tremendously from the actual operation. Consequently, during the design, the uncertainty of annual transportation capacity should be sufficiently taken into account so as to lessen the differences between the design scheme and the actual situation to the best.