Abstract: By using logging method, based on the analysis of the following parameters such as the depth of caprock, porosity, and the depth of source rock, and from the angle of sealing quality and the depth of source rock, this paper discusses the constrain relationship between the caprock quality and gas production, and makes a further a-nalysis on high yield, low yield and water output of gas production. It is suggested that the comprehensive interpretation method with the source- reservoir - cap rock combinations should be introduced into logging interpreta- tion.