Abstract: A pot experiment was set up to investigate the effects of different organic fertilizers on soil microbial biomass and yield of peanut. The results show that economic and biologic yields of peanut are improved by applying fertilizers. The highest yields are for the treatment with compound organic fertilizer containing monosodium glutamate. The total amount of bacteria, epiphyte and actinomyce of soil in the treatment with chicken faeces is highest among the different fertilizer treatments, while the other treatments have only minor differences. Through total DNA extraction, PCR amplification and DGGE analysis of soil microbe, it is found that the certain microbe population increases by the application of various organic fertilizers compared with the treatments of inorganic fertilizer and CK. Also the application of different organic fertilizers improves microbial biomass though to different degrees. Therefore different organic fertilizers affect both soil microbial biomass and diversity trait.