The N_2O emission fluxes and seasonal variations of conservation tillage and conventional tillage in wheat fields were sampled with static closed chamber and measured by gas chromatograph.In order to find the relationship between the N_2O emission and the impact factors,the temperature,water content and miner- alized N of soil were observed at the same time.The results showed that:(1)There were significant seasonal variations of N_2O emissions in wheat fields of conservation tillage and conventional tillage with the same trends of change in different treatments.(2)The N_2O fluxes and seasonal N_2O emission were notable differ- ence between conservation tillage and conventional tillage except no tillage with straw covered(NS).(3)In the wheat growth stage,the fields of conservation tillage were the resources of N_2O emission.(4)The sequence of N_2O emission in different treatments was harrow tillage with straw returning(HS)>rotary tillage with straw returning(RS)>conventional tillage with straw returning(CS)>subsoiling tillage with straw retur- ning(PS)>no tillage with straw covered(NS)>conventional tillage with no straw returning(CN).Compa- ring with conventional tillage,N_2O fluxes of conservation tillage (except NS) were increased.(5)The temper- ature was the primary factor that influenced N_2O emission,N_2O emission was enhanced with the increase of temperature.(6)Water content and mineralized N of soil were not related to N_2O emission.