The relationship between the branching structure of panicles and the number of large vascular bundles in rice was investigated. The cultivars used included japonica and indica lines with different grain appearances. The large vascular bundle number of panicle neck internode was higher in indica than japonica. A significant and positive correlation was observed between the number of large vascular bundles in the panicle neck internode, and panicle weight and spikelet number per panicle. The increase in the number and area of panicle resulted in the increase in panicle spikelet number and panicle weight. Increasing tertiary vascular branch number could improve the appearance of the trait white-belly. Milling quality may be improved by reducing the tertiary number.