Abstract: Effects of different seed sizes on germination, yield and quality of peanuts were investigated in this study under the condition of incubator and field. The results showed that the vigor index and emergence rate of the large seed were higher than those of the small seed, but germination rate and germination index of the large seed were slightly lower than those of the small and middle seed. The highest pod yield was produced by large seed, followed by middle seed, the lowest pod yield was produced by small seed. There are close relationship between the higher pod yield of big seed and the more blooming, strong root activity in a relatively short period, much dry matter accumulation, and so on, which laid a good foundation for larger pod number and higher productivity. The protein content and oil content of peanut were affected by the genetic characteristics and environmental condition of varieties, the seed size had little effect on both of them.