Abstract: The split plot design was adopted with variety as main plot and density as subplot in order to study the dynamic change of growth and development of dwarf sorghum and its response to density in the present experiment. The results showed that dry leaf weight per plant, dry population leaf weight, dry stem weight per plant, dry population stem weigh t and leaf area index of different sorghum varieties first increased and then decreased, and reached the highest value at the flowering stage.While the dry spike weight per plant, dry population spike weight, dry biomass per plant and dry population biomass weight gradually increased and reached the highest value at the maturity stage. In the present study, Longza 22 at D4(25 plants·m^-2) treatment gave the highest seed yield of 9 540.30 kg·hm-2,and Longza 25 at D3(21 plants·m^-2) treatment showed the highest seed yield of 9 710.40 kg · hm^-2.Longza 22 had better density tolerance than Longza 25.