Abstract: In order to study the diversity of Eurotium cristatum in brick tea, the author collected five samples of brick tea from three provinces in China, separated microorganisms golden flower bacteria of No.4, 16, B1, B3, B7, and identified bacterial strains based on the morphology and molecular biology techniques. The experimental results showed that the five strains were Eurotium cristatum and there was a genetic diversity of different sources of strains, the electron microscope results of No.16 strain had the greatest difference from others, which had little holes around“equator”of ascospore. In ITS sequence of phylogenetic tree, cluster of No.4, B1, B3 and B7 was one set, cluster of No. 6 was another set. There may be a subspecies in Eurotium cristatum, which consistent with the morphological results.