Abstract: The plant Tripterygium wilfordii (Thunder of God Vine) is the basis for a traditional Chinese medicine and is found in Zhejiang, Fujian, Hunan,Hubei and Guiz hou provinces, along the Yangtze River. We analyzed the correlation between the content of the secondary metabolite celastrol and environmental factors among 160 individuals of six populations of the plant. The difference in celastrol content was relatively high among populations (max. 1.058 5×10-2g.g-1 in Huangyan,Hunan Province; min.4.988 7×10-3 g.g-1 in Taining, Fujian Province) and relatively low within populations, which indicates that environmental conditions greatly influenced the content of celastrol in T. wilfordii. Regression analysis further revealed a significant negative correlation between celastrol content (Y) and annual sun shine duration (X1), annual rainfall (X2) and N content in soil (X5) (Y=19.308-0.01X1-0.02X2-0.062X5, R=0.917, F=276.561), which indicates the influence of these environmental factors on the content of celastrol in the plant. A strategy to maximize celastrol content is recommended.