| This research on ecological adaptation of maize hybrids in Changtu (Northern Liaoning), Fuxin (Western Liaoning) and Haicheng (Southern Liaoning) was designed by two-factors split plot using Zhendan 958, Tieyan 56, Zhongdi 168, Liaodan 1211, Shenyu 29, Danyu 206, Danyu 405 and Liaodan 527 that have different adaptations. The results showed that maize yields were mainly subject to three meteorological factors including sunshine duration, air temperature and precipitation, especially at the tasseling stage. There were significant or highly significant correlations between the yields and the meteorological factors before and after flowering. Different hybrids in one region and one hybrid in different regions had significantly different yields and variable suitable planting densities. Adequate precipitation during growth period, enough sunshine and air temperature made Changtu a suitable region to plant most hybrids. Five of hybrids tested including Zhongdi 168, Liaodan 1211, Shenyu 29, Danyu 206 and Liaodan 527 were found to be suitable for planting in Changtu, and they had different adaptive densities: 52 500 plants·hm-2 for Zhongdi 168, 82 500 plants·hm-2 for Liaodan 1211, 82 500 plants·hm-2 for Shenyu 29, 45 000 plants·hm-2 for Danyu 206 and 45 000 plants·hm-2 for Liaodan 527. Rich sunshine and air temperature, though relatively poor precipitation compared with the other two regions, led to reduced average yields in Fuxin. Relatively speaking in Funxin, Zhongdi 168 and Liaodan 1211 were suitable to be planted under the densities of 52 500 plants·hm-2 and 67 500 plants·hm-2, respectively. Haicheng had the most highest accumulated temperature and enough water but less sunshine, where Zhengdan 958, Tieyan56 and Danyu 405 achieved the highest yields. Zhengdan 958 and Tieyan 56 had the same adaptive planting densities of 52 500 plants·hm-2, and planting density of Danyu 405 was 37 500 plants·hm-2. |