A complete diallel crossing of four rice parents was done. The large and small vascular bundle numbers in panicle base and the second internode in the F 1 and their parents were analyzed by using additive-dominance model. The results showed that the inheritance of vascular bundle character was mainly predominant by additive effect and the narrow heritability ( h 2 N) was between 0 415 1 and 0 551 9. The cross combinations with significant dominant effects were few and the heterosis of vascular bundle numbers was weak. There were some additive correlations with significant or very significant among the large vascular bundle numbers in panicle base, the primary rachis branch numbers, the secondary rachis branch numbers and their spikelets, and the seed setting rate. These relationships also existed for the small vascular bundle numbers in panicle base with the primary rachis branch numbers, and the small vascular bundle numbers in the second internode with the secondary rachis branch numbers and their spikelets. These relationships could be used as a reference index in breeding.