Recently, great breakthroughs have been made in the exploration of andesite reservoirs in Wulanhua Depression, Erlian Basin, which shows good prospects for exploration in the new area of the depression.However, the unclear understanding of the reservoir-forming model and main controlling factors of andesite reservoirs restricts the normal exploration and development of oil and gas in this area,and most wells fail.In order to further study the reservoir-forming regularity of andesite reservoir, this paper systematically analyses the source, reservoir conditions, reservoir-cap assemblages and reservoir-forming conditions of andesite reservoir,and on this basis, builds the reservoir-forming model of “intra-source-facies controlled composite lithologic reservoir” of andesite reservoir in Wulanhua sag.The results show that the distribution of high quality source rocks controls the material basis of igneous reservoir formation,the distribution of overflow facies controls the development of effective reservoirs,and the development of faults controls the distribution of andesite and hydrocarbon migration.This study provides new ideas and methods for the study of reservoir-forming law of andesite reservoirs, clears up obstacles for later exploration and development deployment, and has certain reference significance for the exploration and development of andesite reservoirs in similar areas.