Abstract: To investigate the diversity of mesophilic bacteria resulting from constant thermal conditions, the soil sample was collected at outfall of thermal wastewater from laundry factory.The culturable mesophilic bacteria were isolated with different medium to obtain pure culture, identified by 16 SrDNA and the data were analyzed in phylogenetic tree.The results showed that the 29 strains in pure culture were obtained from the thermal wastewater outfall soil with different phenotype.The strains were classified into Bacilli, attributed to 5genus and 11 species, including three species of Geobacillus, three species of Bacillus, three species of Anoxybacillus, one species of Ureibacillus, and one species of Thermoactinomyces.The diversity of species was rich, and the resources of species would have potential in practical application.