Abstract:Microorganisms promote biological and biochemical processes of soil. Soil microbial activity can reflect soil biochemistry reaction, which can be used to discuss ecological effects of heavy metal pollution. Field investigation and sampling analysis of polluted mining soils were conducted to discuss effects of heavy metal pollution on soil enzyme activities, basal respiration, qCO2, and potential mineral N in Lawu mine of central Tibet. The results showed that mining soils were polluted by heavy metals, Cu, Zn, Pb and Cd, which led to decreases of enzyme activities and potential mineral N, and increases of basal respiration and qCO2. Multivariate stepwise regression analysis between heavy metal contents and soil microbial activities indicated that effects of heavy metal compound pollution on microbial activities were complex in Lawu mine. Principle component analysis further pointed out that total microbial activities in mining soils were feasible indicators to assess change in soil environmental quality by heavy metal pollution.