Abstract: The kinds and abundance of thallophyta fossils in coal from different places and different ages in China are studied with microscopic examination.It is observed that thallophyta in coals were characterized by different kinds of morphological feature,rich of genera and abundance.The results of thermal modeling suggested that the hydrocarbon generated capacity of sclerotia algal coal is higher than humus coal.Especially the sapropelic coal generated in deep-water area is the important base material of oil.Therefore,the study of coal generation environment and coal generation material must be important for identifying payable area in future.