Abstract: The canonical correlations among kernel quality characters in two top-quality protein maize populations(‘Zhongqun14QPMC₃’and‘Shaanzong 5QPMC₀’) are studied. The results indicate that the negative correlation effect is shown among hardness, kernel denseness, 100-grain weight and bud rate, and 100-grain volume in the physical characters; both lysine content and protein quality are the core characters in the nutrition quality; grain density(or endosperm hardness) is an indirect selecting index of protein quality; grain physical characters and protein quality play an important role in forming lysine; grain protein quality is closely connected with that of endosperm, but it has nothing to do with bud protein quality; and high lysine content and high oil content are unified.