Abstract: This paper reviews some advances in the study of the organic matter thresholds of marine carbonate rocks in China. The authors think that for different demands there should be three different thresholds, i.e. the lowest threshold for marine carbonate source rocks, threshold for effective source rocks and threshold for strategic area selection. Reconstruction of the original organic matter abundance in high-mature marine carbonate rocks has long been in dispute. Hydrocarbon-generating kinetics, combined with the thermal history, may provide a good approach to this purpose, Whether the clay content plays an important role in the enrichment of organic matter in carbonate source rocks and expelling capacity of hydrocarbon is still in dispute. The authors think that the role of the clay content in carbonate rocks remains to be further studied.