Abstract: Using 3 QPM inbred lines as female parents, 5 QPM inbred lines as male parents, 15 crosses were made according to NCⅡ genetic design. Combining ability, heterosis and correlation for yield and quality traits were analyzed. The results were as follows: ①The effects of combining ability among different inbred lines with the same trait and the same inbred line with different traits was highly complicated with the different extend of positive and negative effects. GCAs of kernel depth and water conservancy unit weight for male inbred A was high; GCA of lysine content for female inbred 2 was high; SCA of water conservancy unit weight of cross 3×C was high. ②The correlation analysis indicated that plot yield was very significantly and positively correlated with kernel depth and ear diameter. Lysine content was correlated very positively and significantly with crude fat content, and correlated positively and significantly with crude protein content. ③Heterosis over low parent, mid-parent heterosis and heterosis over high parent were important for lysine content and crude protein content, crude starch content and crude fat content, respectively.