Abstract:［Objective］To evaluate the effect of long-term fertilization on soil microbial community and soil chemical and physical properties． ［Methods］Using a high-throughput pyrosequencing technique，we studied microbial community in the 0－300 cm soil samples covering a 20-year field-experiment with different fertilization applications including inorganic fertilizer alone (N 300 kg/ hm2，P2O5 150 kg/hm2 and K2O 60 kg/hm2) and inorganic fertilizer combined with straw (same application rate of N and P fertilizer combined with 5. 4 t straw)．［Results］Actinobacteria and α-proteobacteria were the predominant groups in the topsoil (0－20cm)．As the soil depth increased，the relative abundance of actinobacteria decreased whereas that of proteobacteria，especially γ-proteobacteria and β-proteobacteria increased and gradually became the dominant groups in the subsoil (20－300 cm)．Long-term fertilizing applications significantly affected soil microbial communities throughout the soil profile，and increased the relative abundance of ammonia-oxidizing archaea at 0－40 cm depth．In addition，agriculture management，e． g．irrigation may be an important driving factor for the distribution of ammonia-oxidizing bacteria in soil profile． Total nitrogen and organic carbon contents were the most influential factors on microbial community in the topsoil and in the subsoil，respectively．［Conclusion］ Long-term fertilizer applications altered soil nutrient availability within the soil profile，which was likely to result in the different microbial community structure between the fertilizer treatments，especially for the subsoil．