Abstract: Field experiments on early, mid and late-season rice were conducted at 54, 136 and 61 sites in 17 counties of Hubei Province during 2006-2008. The objective of the research was to study the effect of nitrogen (N), phosphorus (P) and potassium (K) combined fertilization on rice yield and profit, and to investigate the fertilizer contribution rate and agronomic efficiency (AE) of rice in main rice producing region of Hubei Province. The results indicated that the combined application of N, P and K increased the yield and profit of rice significantly. The average yields of NPK treatment of early, mid and late-season rice were 6502, 8502 and 6888 kg/ha, which were 2153, 2445 and 1908 kg/ha higher than those of CK (without fertilization) treatment, respectively. Compared with CK treatment, profits of NPK treatment of early, mid and late-season rice increased 1691, 2413 and 1413 Yuan/ha, respectively. The fertilizer contribution rates to early, mid and late-season rice yield were 33.3, 28.6 and 27.8 percent, corresponding to 7.2, 7.6 and 6.1 kg/kg of AE, respectively. These results showed that the combination of N, P and K fertilizers significantly increased both rice yield and profit, so balanced fertilization was effective measure to increase rice product.