Abstract: In this study， the moisture content of stem， dry matter accumulation and stalk brix degree were investigated at 5 different growth stages for 3 sweet sorghum and 3 grain sorghum genotypes， respectively. The results showed that moisture content of sweet sorghum was higher than grain sorghum by over 5% throughout the growth period of sorghum except at the booting stage. Significant differences were discovered between sweet and grain sorghum in dry matter accumulation. The dry weight ratio of sweet sorghum stem was greater than that of grain sorghum， which was evidenced that double sink （grain and stalk） existed in sweet sorghum. The levels of stalk brix degree of sweet sorghum increased slowly from seven leaf stage to the booting stage， sharply from booting stage to heading stage， steadily from heading stage to filling stage and showed differences from filling stage to maturity stage. Taken the consideration for both grain and sugar yield， the most suitable harvesting strategy was suggested for sweet sorghum.

Key words: sorghum, brix, moisture content of stem, dry matter accumulation