Distribution area of marine carbonate sediment in our country amount to about 3 million square kilometers and it has been considered as the potential petroleum exploration area all the time. But till today the exploration activity has not got a satisfied result, and the key problem come into contact with is that the facies of quality source rocks is not clear in carbonate sedimentary basin, and the main factors controlling formation of the quality source rocks is not clear either. The paper studied the ocean organism, organic matter distribution characteristics in contemporary marine sediments and ancient marine strata and laboratory modeling. It shows that the main factors influencing the marine organic matter accumulation are organism production index in waters when sediment formation, depositional rates, oxidation-reduction potential of environment when depositing and early diagenesis stage, hot fluids activity in ocean bottom and so on. Among the above factors, organism production index in waters when sediment formation is the key factor, and reducing environment when depositing and early diagenesis stage is favorable condition for organic matter accumulation and preservation, hot fluids activity in ocean bottom is the factor cannot be ignored, depositional rates is the main factor and suitable depositional rates is favorable condition for marine carbonate organic matter accumulation.