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To investigate the ecological safety of Beauveria bassiana in soil, we evaluated the effects of different concentrations of B.bassiana spore suspensions and chemical pesticide (acephate) on paddy soil microbial flora and enzyme activities by a potted trial.DGGE analysis and plating dilution methods showed that B.bassiana can improve the quantity of bacteria and fungi in paddy soil while promoting actinomycetes growth after inhibition.However, acephate reduced the quantity of bacteria, fungi, and actinomycetes in soil.Both bacteria and fungi were found in high abundance in B.bassiana treatment groups.Investigation of enzyme activities revealed that invertase activity declined during prophase, while urease activity decreased later in B.bassiana treatment groups, and there were no significant changes in alkaline phosphatase or dehydrogenase activity.Acephate showed inhibition rates of 45.4, 34.9, 47.3, and 51.7% for invertase, urease, alkaline phosphatase, and dehydrogenase, respectively, on day 10.B.bassiana treatment at 7.5 × 104, 7.5 × 105, and 7.5 × 106 spores/ml showed a higher yield than control and acephate treatment.Overall, when compared with the chemical pesticides acephate, B.bassiana is an effective, environmentally friendly microbial pesticide in this system.