While water chemistry is widely used in oil & natural gas exploration and make good effect, we chosed it in gas hydrate which has similarity with oil & natural gas in origin & surface chemical abnormity exploration in Qiangtang Basin Qinghai-Tibet Plateau. We achieved 19 fountain samples in Qiangtang Basin, and had it tested it in National Gas-geochemisty Key Laboratory Lanzhou Institute of Geology Chinese Academy of Sciencences. According to the test result we recognize that the 19 fountains are mainly fresh or low mineralized water, typed as Na2SO4 & NaHCO3 according to Sulin’s water sorting principle. Hydrogen & Oxygen isotope analysis indicate the mainly rainfall origin of the fountains. Dissolved methane and its carbon isotope 13C test show that it may come from oil or gas hydrate buried deep in the ground. In conclusion that SQ-2 & SQ-17 may point out the possible position of oil & gas or natural gas hydrate deposit.