Abstract: The natural gas market has entered a stage of rapid development in Zhejiang province, and six supply systems of gas source mixed transportation will be gradually formed during the twelfth five-year period. The diversification of gas source has improved the security of natural gas supply system and the interchangeability of different gas sources, however, must been taken into consideration when getting into the main pipeline network due to the differences of natural gas origin, production process, and gas source, especially the air components and characteristics between natural gas and liquefied natural gas. Using Wobbe index method and America Gas Association (A.G.A) method, the interchangeability of five major sources of natural gas in Zhejiang province was analyzed. Referring to the foreign methods of solving gas interchangeability problem, solutions of gas pipeline network supply under the structure of gas source mixed transportation in Zhejiang province are put forward.