Abstract: The similarities and differences of the two modes raised by the effective medium theory were analyzed. Using the logging data and core samples from the drilling hole in the Shenhu area and based on the equivalent medium theory of a physical model, we estimated the saturation of gas hydrate in pore space of the sediment from a well in Shenhu area and calculated the P-wave velocity on different saturation of gas hydrate. Vertical distribution patterns of the gas hydrate in sediment layer was established. The result shows that the gas hydrate in Shenhu area mainly occurs in the depth of 190~220 m. The gas hydrate saturation increases in the beginning and decreases later on with depth. The highest saturation of the gas hydrate in this area may be as high as 45%.