Abstract: The fluorescence alteration of multiple macerals (FAMM)technique is a new method to determine the thermal maturity of source rocks by means of laser Raman microprobe which measures the fluorescence alteration of multiple macerals.It can effectively resolve practical problems such as the widespread occurrence of vitrinite reflectance suppression in thermal maturity assessment of source rocks.The technical advances and the basis of FAMM technique are expounded,the present application progress is introduced and the practical problems of FAMM technique are also pointed out in this paper.The aim of this paper is to urge its application and study in oil and gas exploration and evaluation of oil and gas-bearing basins in China.