Using the continuous cropping soil for pepper production as the research object，the dynamic changes of soil physical and chemical properties，enzyme activity and microbial flora of different continuous cropping years in Jianzha county of Qinghai province were analyzed.The results showed significant effects of continuous cropping in terms of physical and chemical properties，enzyme activity，microbial population and microbial biomass.With the increased years of continuous cropping，the bulk density and electrical conductivity of soil were increased，the pH value of the soil was declined.Moreover，the amounts of organic matters，total nitrogen，available phosphorus，and available potassium were increased at first and then decreased，whereas the concentrations of soil alkaline phosphatase，sucrase，amylase，and catalase showed a downward trend.The content of urease and alkaline protease increased at first and then decreased.In comparison with the control group，continuous cropping resulted in a decrease in the ratio of soil bacteria to fungi，and an increase in the ratio of soil microbial biomass carbon to microbial biomass nitrogen.The microbial community structure of soil has been transformed from “bacterial type” to “fungal type”.