Abstract: The result of determination showed that the N2O flux from the greenhouse was much higher(about 1.39 times) than that from the open field. The N2O flux with irrigation was higher (about 1.17 times)than that without irrigation. With increase rate of urea, the N2O flux sharply increased. The regression equation was y=256 96+1.427x, r=0.9951**.The N2O flux disposed by organic manure (ferment microbial manure) was higher than that by urea within 5 days. Determination of quantity of nitrifiers and denitrifiers found that there were fewer nitrifiers and denitrifiers in the urea treatment compared to CK, but the quantity of denitrifiers rose with the time prolonged. The quantity of nitrifiers disposed by organic manure was a little fewer than that by urea treatment, but there were obviously more denitrifiers.