The establishment of accumulation model evaluation system is a subsystem of natural gas resources assessment export system(GRAES). It has integrated complicated quantitative calculation model with the qualitative evaluation model

therefore the system could reach a higher stage of processing sophisticated logical inference. One of the key technique of the system is to establish mathematical and physical calculation models according to gas accumulation mechanism. The other key technique is to found some new knowledge logical relations that could combine quantitative calculation model with qualitative inference model properly. On this base

the gas accumulation model is established with elastic rocks as the example

and the concepts and inference calculating models of six knowledge logical relations are discussed in this paper.