The effect of rice growth on the mineralization of soil nitrogen was investigated by pot experiment and sealed anaerobic incubation.The results obtained are summarized as follows.Except in the initial stage of mineralization,the nitrogen mineralized from soil organic matter calculated from the sum of nitrogen in whole plant (including roots) and ammonium-N in soil under rice growing condition was 29-62% higher than that in sealed anaerobic incubation being carried out under the same conditions with pot experiment,which showes that the growth of rice plant can considerably promote the mineralization of soil nitrogen.