[Objective] The aim was to investigate the changes in microbial population and soil enzyme activities in rhizosphere soil of two cultivars of Allium sativum L.at different growth stages.[Method]By using white garlic and purple garlic as the experimental materials,the microbial population,and the activities of urease,acid phosphatase and catalase in their rhizosphere soil at different growth stages were measured.[Result]The root exudates of the two garlic cultivars could promote the growth of bacteria,fungi and actinomycetes,and indirectly increase the urease,acid phosphatase and catalase activities in the rhizosphere soil,thereby improving the turnover and circulation of the soil nutrition elements such as nitrogen and phosphorus,and providing a better micro-ecological environment for the later crop.[Conclusion]The study had provided theoretical basis for the ecological research on garlic used as a preceding crop.