Abstract: About 80 greenhouses with different planting years (0-30 a) were selected from the suburb of Beijing, and the change and influencing factors of soil main chemical properties and biological indices in the greenhouse were investigated compared with the open field (CK). The results showed that with the increase of planting years, the pH value fluctuated strongly, the content of available phosphorus (P) continued to rise, and the contents of soil organic matter (SOM), available potassium (K), 8 water-soluble ions and the number of bacteria were increased first and then decreased. Compared with CK, the number of bacteria was increased by 231.33% in 6 - 10 a, and that of fungi was increased by 49.62% in 16 - 30 a. The number of fungi was increased linearly with planting years, and the regression equation was y = 3E + 07x + 2E + 08 (R² = 0.9424^**). The activities of α-glucosidase (AG), β-D-glucosidase (BG) and phosphatase (AP) were increased linearly with planting years. Redundancy analysis showed that the changes of SOM, available P, available K and some salt ions (K⁺, Mg²⁺, NH₄⁺) led to the changes of enzyme activities and microbial quantity. Soil quality and sustainable productivity can be improved only by reducing fertilizer input, changing fertilizer types and adding beneficial microbial agents, as well as planting idle crops and deep tillage.