CO₂ and N₂O emission fluxes and seasonal variations of soybean fields in lower reaches of Liaohe Plain were measured during two years synchronously for the first time by static closed chamber-gas chromatograph to find relationship between two gases' emission fluxes and impact factors. Results showed significant seasonal variations of CO₂ and N₂O emissions in soybean fields; Soil temperature and moisture were two important factors that influenced CO₂ and N₂O emission in soybean fields, while soybean plant was another important factor that increased N₂O emission fluxes; N₂O emission flux of normal treatment were 2.28 and 1.80 times of CK in 2004 and 2005, respectively.