Abstract: Based on a field experiment and “Zhengdan 958” genotype, the effect of different levels lodging on leaf area index (LAI), yield and its components of summer maize were studied. The results showed that LAI of summer maize gradually reduced, which there was significant different at each treatment, with the gowth period went on. LAI was the smallest under severe lodging (A00) conditions. when the degree of lodging increased, ear length, grains per spike and kernel weight decreased, yield and biological yield reduced; at the same time, yield cut rate increased, A60、A45、A30 and A00 treatment cut 5.8%, 24.3%, 52.2% and 89.9%, respectively, compared with the control treatment without lodging. The results would provide reference for high-yield cultivation of summer maize.