Abstract: The fluorescence alteration of multiple macerals(FAMM) analysis approach is established by using argon ion laser with 488 nm as light source of laser Raman spectrograp and used in analysis of effective source rocks from Dongying depression with significantly suppressed vitrinite reflectivity. The results show that the better of organic matter type is, the higher of level of vitrinite reflectivity suppression is. The true thermal maturity of effective source rocks from Dongying depression is mainly at 0.64%~1.30% instead of 0.37%~1.10% from actual measurements.