[Objective] The effects of membrane degradation residuals on community structure and diversity of soil microorganisms were investigated. These results were expected to provide theoretical references for polyethylene film engineering selection with respect to its molecular weight and degradation model. The selection is inferred that an environmental-friendly kind of polyethylene have the minimum negative effects on soil environment. [Methods] Orthogonal experiment L₉(3⁴) and the PCR-DGGE measurement were adopted to analyze the community structure of microorganisms in soil treatments which were mixed with plastic powder in three years. [Results] The results showed that soil properties were the main factors which influence the variations of community structure and diversity of soil microorganisms. The polyethylene with number-averaged molecular weight of 2 000 and linear low density polyethylene(LLDPE) in the soil which treated with large membrane degradation residuals has a more obvious influence on the community structure of microorganisms than the influences that other matched group been observed. The community diversity of microorganisms in the soils which were mixed with low molecular weight polyethylene and large molecular weight polyethylene with large membrane degradation residuals became more abundant. The complexity coefficients of soil microorganisms in different test treatment increased with 18.7% and 2.6%, respectively. [Conclusion] Differences of community structure and diversity of soil microorganisms among the treatment were visible, and the number of soil microbial in all treatments showed an increasing trend when compared with the number of the corresponding control group.