Soil simulation experiment by static absorption and soilculture methods was conducted to study the nitrogen release and ammonia volatilization decrease from different amounts of slow release coated urea combined with conventional urea.The results showed that the mixing treatments i.e.SRU25,SRU45,SRU65,SRU100 with 25%,45%,65%,100% of slow release nitrogen ratio respectively,reduced the amount of ammonia volatilization by 19.88%,25.94%,42.84%,46.13% respectively compared with treatment of urea used only(SRU0).In the prophase of cultivation,the content of total nitrogen,available nitrogen and ammonium nitrogen for SRU0 was higher than slow release urea treatments.With the prolongation of culture time,total nitrogen,available nitrogen and ammonium nitrogen of SRU0 reduced more sharply than slow released urea treatments,and these three nitrogen parameters were higher under slow release urea treatments.Nitrate nitrogen gradually increased with time.45% slow release urea+55%conventional urea(SRU45)was the best treatment,which not only supplied a prescribed amount of necessary nutrients,but also decreased the ammonia volatilization,and saved the economic costs.