Abstract: To understand the diversity of contaminative microorganisms that may affect the result of rice （Oryza sativa L.） seed germination rate test, high-throughput sequencing and taxonomic identification for the moldy pollutants produced during the test were carried out on eight rice seed samples collected from the annual seed quality inspection task in Guangdong Province, China. The results showed that a total of 208 genera, 104 families, 71 orders, 35 classes, and 20 phyla of bacteria were identified from the moldy pollutants, with Proteobacteria as the dominating phylum whose average relative abundance was 63.2%, and Gammaproteobacteria as the dominating class （average relative abundance： 48.2%）. Clostridium, Burkholderia, Enterobacter and Klebsiella were the four most abundant bacterial genera whose average relative abundances were 20.2%, 18.0%, 7.5% and 5.1%, respectively. On the other hand, a total of 87 species, 85 genera, 61 families, 37 orders, 17 classes, and 7 phyla of fungi were identified in the aforementioned moldy pollutants. Ascomycota and Mucoromycota represented 59.0% and 18.5%, respectively, of the fungal community. Eurotiomycetes （42.0%）, Mucoromycetes （18.5%） and Sordariomycetes （12.9%） were the three most abundant fungal classes, whereas Aspergillus （38.4%）, Rhizopus （18.5%） and Fusarium （9.0%） were the three most abundant genera. Furthermore, Aspergillus flavus （average relative abundance： 31.6%） and Rhizopus microsporus （average relative abundance： 16.4%） made up near one half of the fungal abundance.

Key words: rice （Oryza sativa L.） seed, germination rate test, contaminative microorganisms, diversity, identification