Abstract: To obtain excellent breeding groups with high combining ability, we carried out the half-sib recurrent selection using ‘yunlun1’ group. ‘Chang 7-2’was used as testers to cross with the superior individuals selected from the ‘yunlun1’ C4 group, then 20 superior plants were identified and produced the C5 group after mixed pollination by using the same amount of seeds. The results showed that the plant height, ear position and stem rot rate of the improved C5 population were decreased by 4cm, 2cm and 3.5% respectively. There was an extremely significant difference between the single plant among groups for the combination ability, and yield gain was expected to increase by 7.7%. Compared with all the test cross varieties，ear position and stem rot rate of selected test cross varieties were decreased by 0.7cm、6.3%，ear length、kernel number per row 、kernel ratio, stay-green degree increased by 0.1cm、0.6、0.4%、0.3 respectively，but plant height and moisture content increased by 0.3cm and 0.2% respectively, ear width、kernel row number、100-kernel weight remained unchanged .The variation coefficients of each trait were decreased and still below 10% mostly except moisture content and 100-kernel weight. Expanding the groups、increasing number of tester、integrating new germplasms, as well as strictly controlling plant height, ear position and growth period upon individual selection shoud be considered during further improvement.