Abstract: Surveying data for wind lodging disaster happening in Nanyang of Henan Province in August 1, 2013, were used to analyze the effects of strong wind lodging at pre and posttasseling stages on growth and yield of summer maize, and to determine the differences in lodging resistance among varieties and the suitable sowing time for summer maize. The survey included two varieties of summer maize, Xundan 20 and Zhengdan 958, with five and three sowing dates, respectively. The lodging was divided into four types, i.e., root slope (RS), root lodging (RL), stem bending (SB) and stem broken (SBK). The results showed that wind lodging occurring at pre and posttasseling stages resulted in high lodging percentages for both varieties and all sowing dates. The lodging percentage of Xundan 20 variety ranged between 86.0% and 98.5% for five sowing dates. For Zhengdan 958 variety, it ranged between 60.0% and 76.4% for three sowing dates. After tasseling, the earlier the sowing date, the lower the lodging rate occurred. The main lodging types happening around the tasseling stage were RL with the lodging rate of 53.0%-84.3% for sowing dates Ⅱ-Ⅴ of Xundan 20. The main lodging type for sowing date Ⅰwas SB with the lodging rate of 37.5%. Lodging reduced the aboveground dry matter with the greatest reduction rate occurring in SB, followed by RS and RL. Lodging increased the allocation of dry matter to leaves and stems, but decreased the allocation to spikes. RL and SB shortened the length and diameter of spike, and reduced the grain number per spike. The lodging occurring after the tasseling stage also reduced 100grain mass. RS had no significant effects on spike characters and yield components. The lodging had serious effects on the yield of summer maize. The yield loss was highest for SB with the reduction percentages of 74.2% and 68.7% for Xundan 20 and Zhengdan 958, respectively. SB occurring before the tasseling stage would lead to a complete crop failure. RL decreased the average yield by 46.3% and 46.5% for Xundan 20 and Zhengdan 958, respectively. RS decreased the averaged yield by 8.4% and 13.2% for Xundan 20 and Zhengdan 958, respectively. The mean  yields of Xundan 20 and Zhengdan 958 were 4959.9 and 6026.1 kg·hm^-2 after the wind lodging, respectively. The later the sowing date, the higher the yield loss rate was observed for Xundan 20, however, there were no significant difference in yield loss among different sowing dates of Zhengdan 958. In general, Zhengdan 958 had stronger lodging resistance than Xundan 20.