Abstract: Reasonable plant density can construct the good population structure, enhance light energy utilization efficiency, optimize population physiological function, and give full play to the potential yield of sorghum varieties. The purpose of this research was to investigate the effects of plant density on growth, population physiological indices, grain yield and its component factors of brewing sorghum (Sorghum bicolor L. Moench var. ‘Jinza No. 23’) under varying plant densities (45000, 75000, 105000, 135000 plants/hm2). The experiment was conducted in the randomized complete block design (RCBD) with three replications. The results showed that, plant height of sorghum was significant increased, whereas stem diameter was thinned as plant density was increased. Leaf area index (LAI), Leaf area duration (LAD), total LAD were significant increased, but net assimilation rate (NAR), crop growth rate (CGR) and transmission rate decreased with increasing plant density. Dry matter weight per plant declined, whereas dry matter weight of sorghum populations significantly increased when plant density increased. When the plant density was at the ranges of 45000-105000 plants/hm2, grain yield significantly increased with increasing plant density. The grain yield increased by 13.8% in 105000 pants/hm2 as compared to plant density in 45000 plants/hm2. Panicle number per unit area increased, but grain number per panicle decreased as plant density increased. 1000-grain weight was not influenced by plant density variety. Correlation analysis revealed that the relationship between plant density and LAI, LAD, biomass and grain yield of sorghum were significant and positive correlation. The relationship between plant density and transmission rate, NAR and CGR was significant and negative correlation. This study indicated that plant density significant influence on the population physiological indices, grain yield and its component factors of sorghum. Optimal plant density for brew sorghum ‘Jinza No. 23’ production in this environment is 105000 plants/hm2. It can construct the good population, coordinate population growth and individual growth, and optimize population physiological function, which made both biomass and grain yield to achieve higher level.