NH3 volatilization is one of important ways for nitrogen loss.To clarify NH3 volatilization regulations and major influence factors is important for N loss assessment and adjustment.Effects of fertilization period,N application level,the application of organic fertilizer and NH+4 concentrations on NH3 volatilization were studied to reveal the main characteristic of NH3 volatilization in Jiaxing in 2013 using a method of a continuous air flow enclosure.The results showed that NH3 volatilization mainly occurred in the first 5 days after basal fertilization and NH3 volatilization rate decreased with the time.After topdressing at the panicle initiation stage,NH3 volatilization rate was much lower(< N 5 kg·hm-2·d-1)than that after basal fertilization,and NH3 volatilization in this stage fluctuated due to the falling air temperature and rainfall.There was a positive linear correlation between the amount of NH3 volatilization and N application level,and the percentage of N lost from NH3 was 17%～28%.As to the treatment of N225+M,the amount of NH3 increased significantly and the percentage of N lost reached the maximum.The improvement of NH3 volatilization by dried chicken manure was little.For the purpose of high utilization and low loss of nitrogen fertilization,N application level should be below 225 kg·hm-2,and water and nitrogen coordination should be enhanced.