Abstract: The effect of different formula of NPK and top dressed twice on rice growth in typical double cropping rice area, which located at Kaihui, Ganshan, Matang and Xinqiang Town, were studied on field experiment in order to select the formula of compound fertilizer and top dressing mode for double cropping of rice production in Hunan. The results showed that, the rice yields for the optimized formulated fertilizer treatment, which increased the proportion of phosphorus and potassium and reduced its nitrogen fertilizer by 7.5 kg/hm², could ensure early rice stable yield and increased late rice yield by 187.5-378.0 kg/hm² compared with the conventional complex fertilizer (N-P₂O₅-K₂O formula as 20-10-10 for early rice and 26-10-13 for late rice). The N-P₂O₅-K₂O formula 18-14-16 of optimized formulated fertilizer was suitable for early rice production, and the other N-P₂O₅-K₂O formula 18-9-16 was suitable for late rice production. The rice yields for top-dressing at tillering stage, booting stage increased by 187.5-382.5 kg/hm² and 258.0-415.5 kg/hm² for early and late rice, and the nitrogen use efficiency increased 10.9-24.2 percentage points (31.5%-51.1%) for early rice and 8.3-13.4 percentage points (36.2%-64.9%) for late rice compared with the top-dressing at tillering stage.