Abstract: Paeonia suffruticosa ‘Luoyanghong’ was used as experimental material, and different LED light sources（red light（658 nm）,blue light（461 nm）,green light（520 nm）,yellow light（596 nm） and common fluorescent lamp（CK）） were used to study the effects of different light qualities on the growth, sugar metabolism and related enzyme activities of Paeonia suffruticosa in vitro, in order to provide reference for improving the quality of Paeonia suffruticosa in vitro.The results showed that overall growth of test-tube seedlings were better under red light, the fresh weights（total, stem, leaf） and dry weights（total, leaf） were the highest under blue light treatment, the stem dry weight was the highest under red light treatment, and the leaf fresh weight and total fresh weight were the lowest in the yellow light treatment.The fresh weight（stem） and dry weights（total, stem and leaf） were the lowest under the CK treatment, the total fresh weight was higher in the green light treatment than in the red light treatment, and the total dry weight was the opposite.The contents of soluble sugar, sucrose and fructose were the highest under red light treatment, and glucose was the highest under blue light treatment.The activities of sucrose synthase（SS） and sucrose phosphate synthase（SPS） were both highest in the red light treatment, and the activities of SS and SPS were lower under green light treatment and yellow light treatment.The activities of acid invertase（AI） and neutral invertase（NI） were the highest under blue light treatment, AI activity was the lowest under red light treatment, and NI activity was the lowest under yellow light treatment.In conclusion, it showed that blue light treatment was beneficial to the dry and fresh weight of Paeonia suffruticosa in vitro;red light treatment increased the contents of soluble sugar,sucrose and fructose,and blue light treatment increased the glucose content;yellow light was unfavorable to the growth of test tube seedlings;the changes of dry and fresh weight of green light treatment and red light treatment were probably related to the high activity of SS and SPS and low activity of AI and NI under red light treatment,which led to the increase of sucrose content and thus dry weight.