Jinhu Sag is a faulted lake basin developed since the Late Cretaceous. The identification of effective source rocks plays an important role in oil and gas exploration. Based on a large number of analytical tests in Sanhe Subsag of Jinhu Sag, geochemical characteristics of source rocks in the second number of Funing Formation (E1f2) have been systematically analyzed. According to the principle of material balance in the evolution of source rocks, the current residual total organic carbon contents have been restored to the total organic carbon value before hydrocarbon generation and expulsion. The lower limit of effective source rocks is determined by the relationship between generated hydrocarbon and adsorbed hydrocarbon. According to the lower limit, effective source rocks in the study area are comprehensively evaluated. The research results show that type II1 occupies most of the organic matter types, w(TOC) is 0.05% to 5.28%, (S1+S2) is 0.01 to 33.29 mg·g-1, vitrinite reflectance (Ro) is 0.4% to 1.2%. Thermal evolution of source rocks has reached a mature stage. The recovery coefficient of source rocks is 1.05～1.25. Using recovered total organic carbon value to identify effective source rocks avoid the deviation that subjective factors and physical simulation experiment conditions lead to. The lowest limit of TOC contents of effective source rocks is 1.6%. Combining with log prediction, the distribution and thickness of effective source rocks has been further ascertained. The deep depression zone is the main distribution area of effective source rocks in Sanhe Subsag. The thickness of effective source rocks reaches more than 160m.