Abstract: With the hydrate exploration geochemistry method,it is conducted that the vertically cross section combined indexes geochemistry research on Jurassic coal beds met by Dafesi Borehole D 4 in Dafesi coal field.The results indicate that the hydrate material in all samples collected from cross section is the preliminary stage's hydrate products from coals,being of same characteristics;from coal bed up to surface soil the hydrate material of samples showed out the up migrating indicates.It is confirmed that hydrate of underground coal bed is of geochemistry indicating,therefore,it is feasible to find coal/coalbed gas with the methods of exploration geochemistry.