Abstract: The study of the main controlling factor on hydrocarbon accumulation and evaluation on the favorable block has been con-ducted for Guanjiapu district in Dagang Beach District. Three main understandings have been achieved. Firstly, there are three main controlling factor on hydrocarbon accumulation, including unconformable surface, faults and the combination of hydrocarbon trans-portation layer. Secondly, three hydrocarbon accumulation models have been established, including ladder accumulation model. In the slope zone, "Y" front style accumulation model. And the secondary fault accumulation model. Thirdly, three geologic evaluation methods (geologic risk stochastic method, fuzzy mathematic evaluation method, and expert system method) have been developed for Guanjiapu district. Through comprehensive geologic evaluation, it is concluded that from D18 faulted nose to Zhuanghai 4X1 Fault Block, Zhuanghai Well block-8, Zhuanghai Well block 808X1, the reservoirs become poor gradually in Guanjiapu district.