Abstract: In order to clarify the effect of planting density on the four factors of the highest seedling and yield and seed production yield of two-line sterile line Li S, and provide reference for the high-yield seed production of Li S, five treatments with different planting densities were set up, and the nest spacing of treatments A-E was 16.5 cm × 16.5 cm, 16.5 cm × 19.8 cm, 16.5 cm × 23.1 cm, 16.5 cm × 26.4 cm and 16.5 cm × 29.7 cm, respectively. The effects of planting density on the heading date, maximum seedling, yield and seed production yield of Li S were studied. The results showed that the highest number of seedlings and effective panicles were found in treatment A, which reached 3.835 million tillers·hm⁻² and 2.525 million panicles·hm⁻², respectively. The highest number of grains per panicle was found in treatment E, which was 190.5 grains per panicle. The highest allogamy fructification rate, thousand seed weight and seed production yield were found in treatment C, which reached 53.7%, 25.9 g and 3909.2 kg·hm⁻², respectively. Different planting densities significantly affected the maximum number of tillers, the number of effective panicles, the number of grains per panicle and the yield of seed production. The maximum number of tillers and the number of effective panicles decreased with the decrease of planting density, while the number of grains per panicle increased with the decrease of planting density. The allogamy fructification rate and thousand seed weight were less affected by the planting density, and the seed production yield was affected by the four factors such as planting density, ear sprouting period and yield. The best spacing was 16.5 cm × 23.1 cm.