There are a large number of microorganisms in the air, which are closely related to human production and life can benefit mankind and endanger human life and health. The method for measuring the air microorganism comprises include a solid method (plate dropping method, impact method and filtration method) and liquid method. The species and sources of air microorganisms and their determination methods were introduced. It is proposed that the air microorganisms real-time proposed should be continuously monitorel in real-time. The structure, distribution characteristics and dynamic variation of air microbial community should be studied systematically, and provided theoretical basis for the formulation of relevant environmental protection measures and regulations.