The grain-filling properties of three paddy rice of Gangyou 527,Dyou 363 and Shanyou 63 under four different irrigation methods were fitted by Richards growth equation to study the differences in grain-filling properties.The results indicated that,compared with submerged irrigation,damp irrigation and the treatment C(controlled damp irrigation before booting stage,rational irrigation at booting stage,wetting-drying alternation irrigation from heading stage to mature stage) had higher grain-filling rate,and were favorable to grain-filling and the enhancement of seed setting rate,1000-grain weight and grain yield.But dry cultivation had lower grain-filling rate that had a negative effect on grain-filling,especially weak potential grain-filling.Dry cultivation decreased seed setting rate and 1000-grain weight,which led to low grain yield.