Abstract: Field rice culture experiments were conducted to study the distribution of the average grain weight within different parts of panicle of two-line supper-hybrid rice (peiliangyou E32 and peiliangyou 500) in this paper. The results show that the distribution of average grain weight of different panicle parts is normal distribution, the variance’s homogeneity among parts, however, varies with the grain-filling characteristic of the variety. Very significant difference of average grain weight among parts of panicle is also found.