Based on a long-term fertilization experiment in Huangnitu soil (a major soil type in the Taihu Lake Region), relationships of fertilizer combination with soil nitrogen supply, plant nitrogen absorption, and rice grain yield were studied. Results showed that soil nitrogen supply was positively related to rice nitrogen absorption, as well as rice nitrogen absorption to rice grain yield. When N was applied at a rate ranging from N 161.00~241.00 kg/hm², rice grain yield was in the range of 7285~8172 kg/hm², basically the same as the yield in the farmland. When the soil was not fertilized for a long time, rice grain yield remained at a certain level. When only organic manure was applied for a long time, soil N supply fell short to meet the need of rice for growth and thus rice grain yield decreased. A long term of withholding P and K would not affect much yield of the crop.