Abstract: In this paper, the problem of optimal selection of natural gas pipeline systems design is studied.Natural gas pipeline systems design is very complex. It is associated 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, compress ratio, compression station's number and expenses etc. with different weights. The judging indexes are obtained through fuzzy relationship operation. Consequently the optimal selection of natural gas pipeline systems design is obtained. The fuzzy decision method can be taken as a theoretical base and the new design method can be used in the engineering design.