Abstract: The problem of optimal selection of natural gas pipeline systems design is studied in this paper.Natural gas pipeline systems design is very complex. It is associated with a lot of fuzzy factors. According to the actual information of the project, the effect factors of the optimal selection of natural gas pipeline are regarded as fuzzy variables, such as diameter, pressure, compression ratio, compression station's number and expenses etc. with different weights. The judge indexes are obtained through the fuzzy relationship operation. Consequently, the optimal selection of natural gas pipeline systems design is obtained. The fuzzy decision method can be the theory bases and the new design method for the engineering design.