Abstract: 【Objective】 Explored the effects of biodegradable film on dry matter distribution and yield components factors of sweet potato. 【Methods】 The field experiments were conducted to explore the effects of different plastic film mulching on dry matter weight， agronomic traits and yield formation factors of sweet potato. 【Results】 The results showed that the dry weight of stem was as follows： the ordinary film treatment>the biodegradable film treatment>the no film treatment. There was no significant difference between the ordinary film treatment and the biodegradable film treatment （P<0.05）， the film mulching treatment was significantly higher than the no film mulching treatment； The dry weight of tuber was as follows： the biodegradable film treatment>the ordinary film treatment>the no film treatment， and there were significant differences among the treatments； The weight per plant and the number of tubers per plant of the biodegradable film treatment were the highest， the ordinary film treatment was followed， and the T/R value （ratio of crown to root） of the biodegradable treatment was the lowest， compared with the ordinary film treatment and the no film mulching treatment， the biodegradable film treatment was significantly reduced 13.68% and 22.64% respectively； The dry matter rate， starch rate， commercial potato rate， fresh potato yield and dry potato yield of the biodegradable film treatment were the highest； The correlation analysis showed that there was a significant positive correlation between fresh potato yield and dry matter rate， and negatively correlated with T/R value and dry matter rate of stem. 【Conclusion】 Different plastic film mulching had different effects on dry matter distribution and yield components factors of sweet potato， The performance of biodegradable film was better than the ordinary film and the no film mulching.