Abstract: Six cultivation modes were constructed by different nitrogen application, planting density, and water management under the condition of total amount of rape straw returned to the field. And the effects of different cultivation modes on rice yield formation and fertilizer utilization were investigated during the rice growing season. The results showed that compared with normal nitrogen application, planting density and water management （T2）, normal planting density and low nitrogen application （T4） decreased rice grain yield and high planting density （T3）, high planting density with nitrogen reduction （T5） and water control in early growth stage（T6） increased rice grain yield by 6.96%, 3.24% and 8.96%, respectively. In addition, rice grain yield of no nitrogen application （T1） was significantly lower than other treatments. Moreover, although reduce the individual grain number per panicle, high planting density with nitrogen reduction（T5） improved population size, thus increased rice grain yield and nitrogen use efficiency.

Key words: rape straw return to the field, cultivation mode, rice grain yield, nitrogen use efficiency