Heading date is an important character, which determines the region and season adaptability of crops. Making clear the suitable planting regions for different foxtail millet cultivars is very important to production practice. 160 foxtail millet resources were investigated for nine traits (e.g. heading date, plant height, panicle length, panicle weight and so on) at Hainan, Luoyang and Jilin in two consecutive years. Correlation analysis showed that a negative correlation was existed between heading date and 1000-grain weight across three regions, but a positive correlation was existed between heading date and plant height, leaf number, panicle length, panicle diameter, panicle weight, branch number per panicle and grain weight per panicle at Hainan and Luoyang, a minor negative correlation was existed between heading date and grain weight per panicle at Jilin, which indicated that with the proper delay of heading date, the grain yield of foxtail millet could be increased by grain number increasement, while excessive delay of heading date might lead to decline of production potential. Variance analysis showed that heading date had significant effect on plant height, leaf number, panicle length, panicle diameter, panicle weight, branch number per panicle, grain weight per panicle and 1000-grain weight (P<0.05) across three regions. At Hainan, with the delay of heading date, grain weight per panicle gave an increasing trend. The cultivars with their heading date longer than 40d possesed the largest grain weight per panicle. At Luoyang, the cultivars with their heading date ranged from 50d to 60d possesed the highest grain weight per panicle. At Jilin, the cultivars with their heading date ranged from 70d to 80d possesed the highest grain weight per panicle. The average grain weight per panicle of each variety across three regions was measured and based on which 53 broad ecological adaptability foxtail millet varieties were screened out. The optimum regression equations between plant height, leaf number, branch number per panicle and heading date were established across three regions. This study concluded that within a certain heading date range, the yield of foxtail millet was increased by increasing grain number but not 1000-grain weight. The selected broad ecological adaptability resources and the established regression equations provided foundation for broad-adaptability cultivar breeding and accurately selection of plant height, leaf number and branch number per panicle by heading date information.