The microheterogeneity in the sand reservoirs is represented by the pore nat-ure, clay mineral composition and pore throat distribution. Through the conven-tional thin section, injecting thin section and SEM observations and X-rayanalysis of clay minerals and pattern analysis of pore structure, it has been re-vealed that the sandstone of the First Member af the Kongdian Formation of theZaoyuan Oilfield, Dagang, is intermediatcly to strongly heterogeneous reservoir rock, while tho Second Member sandstone of the Kongdian Formation is stronglyheterogeneous reservoir rock. Microheterogeneity models for various horizons andthe related measures for enhancement of oil revocory are presented in the paper,which can improve the results of development.