Abstract: The objective is to study straw returning technology in the rice region of southern China, and to provide technical support for substituting straw returning (rapid) decomposition for some nitrogen and reduce nitrogen fertilizer use scientifically. Under the condition of straw returning, different decomposing agent quantities and nitrogen reducing combinations were set up, rice yield and nitrogen use efficiency were detected. Reducing 20% (17%-33%) nitrogen quantity under straw returning model, the average yield was slightly lower than that of conventional fertilizer model. However, there was difference between rice cultivars. The yield of‘Huahang 48’with the treatment of reducing 1/6 nitrogen quantity, 30 kg/hm2 decomposition agent and 60 kg/hm2 decomposition agent, was slightly higher than that of the control. The yield of‘Guang 8 youjinzhan’with the treatment of non decomposition agent and reducing 1/6 nitrogen quantity, 60 kg/hm2 decomposition agent and reducing 1/3 nitrogen quantity, was the highest, but the difference was not significant. In addition, nitrogen agronomy use efficiency and partial factor productivity of‘Huahang 48’under the straw returning model increased by 60.2% and 35.4% , respectively. Rice cultivar selection and straw returning (rapid) decomposition instead of nitrogen reducing is feasible, it is an effective way for nitrogen reducing and rice stable yield.