Biological treatment provides an cost effective and environmentally friendly alternative for many waste gas emissions. Biological waste air treatment is achieved at ambient temperatures, it does not generate secondary pollutants, such as nitrogen oxides, it has become in many instances the method of choice for the control of low concentrations of odors, volatile organic compounds, or hazardous air pollutants in large air streams. A significant body of knowledge and experience has been generated on biological waste gas purification. Examples of waste gas treatment are presented in this paper, such as at municipal wastewater treatment plants, emission from live stock industries, sulfur emissions from industries. This paper discusses the problem of how to prevent biomass clogging and introduces the application of molecular biotechnology in biologeical treatment.The development trend of the Biological treatment are discussed.We hope the biological treatments can gain widely application in China.