Abstract：The acreage bearing likelihood ratio method was adopted to assess oil shale resources in the fault depression basin. This method is simple and convenient. Main geological parameters controlling the generation and enrichment of oil shale was optimized in terms of the development characteristics of oil shale and its metallogeny and enrichment mechanisms in the fault depression basin. Then the analogy coefficients of the assessment area were figured out by quantifying the qualitative binary status of these geological parameters. Finally, the authors assessed oil shale resources of the assessment area in term of the distribution function of oil shale resource abundance of the anatomy area. The results show that oil shale forecast resources of Maoming basin are equivalent to the identification resources from the first “National Oil Shale Evaluation” at the probability of 65%, and the oil shale forecast resources of Maoming basin are equivalent to the identification and forecast resources from the first “National Oil Shale Evaluation” at the probability of 50%.. Therefore, the acreage bearing likelihood ratio method can effectively assess oil shale resources of the basins with middle-low exploration extent.