Abstract: To further clarify molecular metabolism of high yield super-hybrid rice, this paper studied differential expression patterns of leaf proteins in super-hybrid combinations “Ⅱ Youhang No. 2” and hybrid combinations “Shanyou 63” during grain-filling. The proteomic approach, which was based on two-dimensional electrophoresis (2-DE) and mass spectrometry (MS) was used in the study. A total of 22 differentially expressed proteins (at a significant level) were noted, and 20 of which were eventually identified. Further analysis of relative functions and expression abundances showed advantages of “Ⅱ Youhang No. 2” in photosynthetic metabolism, defense, gene-transcript regulation, cell growth, energy metabolism, compared with “Xianyou 63”. The advantages maybe the internal agents of “source” property of “Ⅱ Youhang No. 2” leaf in grain-filling stage. The study revealed the source properties of high yield super-hybrid “Ⅱ Youhang No. 2” at differential proteomic levels. This, to some extent, enriched the source-sink-flow theory and provided a theoretical basis for super-hybrid rice breeding.