Abstract:〖WT5HZ〗Abstract: 〖WT5BZ〗 By using correlation analysis, this paper studied the relationships of soil micr obial quantity and biomass with soil physical and chemical factors and enzyme ac tivities in highway shelter-forests of Tarim Desert, aimed to approach the inte ractions between microbes and environmental factors in aeolian sandy soil of ext remely arid area. The results showed that soil microbial quantity and biomass in the shelter-forests had an increasing trend with the decrease of soil bulk den sity and particle size (R<-0.84) and the increase of soil moisture content and p orosity (R>0.85), with the correlation between soil microbial biomass and soil b ulk density as the key. Soil microbial quantity and biomass were positively corr elated with soil nutrient contents, mainly caused by the correlations of soil ac tinomycetes and microbial biomass C and P with soil available nutrients. Greater differences (R=051〖KG-*2〗-〖KG-*7〗091) were observed in the correlations of soil enzyme ac tivities with soil microbial quantity and biomass, which was mainly determ ined by the correlations of soil invertase and phosphatase activities with soil actinomycetes and microbial biomass C. The increase of soil salt content was not favorable to the accumulation of soil microbial biomass (R<-071), and there w as a higher positive correlation (R>063) between soil microbial amount and bio mass. In practice, good soil condition should be established in the forestlands of arid area for the development of soil microbes and the promotion of soil matt er cycling.