【Objective】To explore effect of lipid content on major qualities of japonica rice grains and to provide a theoretical basis for breeding high quality rice in the future. 【Method】Twelve japonica rice cultivars were selected as the materials. Their lipid contents, protein contents, cooking and eating qualities and processing qualities were measured respectively, and the relationships were analyzed to find out the effect of lipid content on major qualities of japonica rice grains. 【Result】The lipid contents and breakdown values of D79 and Koshihikari were significantly higher than those of other 10 cultivars (P<0.05), but setback values of both cultivars were evidently lower than those of other cultivars (P<0.05). Koshihikari showed the highest taste value (84.2), and then followed by D79 and W140, which were significantly higher than those of other nine cultivars (P<0.05). No significant correlation was found between lipid content and processing quality or protein content (P>0.05). Lipid content exhibited the significant negative relationship with amylose content (P<0.01), and the positive relationship with taste value or breakdown value (P<0.05). 【Conclusion】Enriching lipid content and reducing amylose content could be beneficial to improve the cooking and eating qualities of japonica rice grains.