Abstract: Oil and gas exploration of Mesozoic strata in Chaoshan depression of Dongsha sea area is believed to have good prospect. Because of its low exploration and study level caused by the limitation of seismic data, oil and gas distribution there is unknown. In order to strengthen the research on the distribution and enrichment of oil and gas in the west of Chaoshan depression, the authors first applied microbial hydrocarbon detection technology to study its oil-bearing property of geological targets. Based on the theory of light hydrocarbon microseepage, the authors used the method of geological microbiology and geochemistry directly detect the anomaly of microbes and adsorbed hydrocarbons on the surface of the study area, and predicted the enrichment area of oil and gas in the underlying strata of the study area as well as its oil or gas properties. The results of microbial hydrocarbon detection show that microbiological anomaly is massively developed in the slope area of the western depression, suggesting that the intensity of light hydrocarbon micro seepage is relatively large in the study area, and there may be oil and gas enrichment zone. Acidolysis hydrocarbon analysis shows possible existence of oil and gas properties for dry gas and condensate oil and gas. The results of microbial hydrocarbon detection indicate that the Mesozoic strata in the Dongsha sea area has a good potential for oil and gas resources.