Abstract: Stem end of Gynostemma pentaphyllum has the special way to survive winter and breed through burrowing into soil to convert to stem-to-rhizome.In this paper, the stem apexes were placed in lightproof plastic tubes, and the content of phytohormones and sugars in the apexes from aerial stem-to-rhizome transition were detectived. The results showed that the aerial stem apex could develop into rhizome in 8 days, through yellowing and swelling stem stage and abnormal stem stage in darkness. Compared with the control in light, the contents of IAA, GA and JA increased to the maximum value at the yellowing and swelling stage. These phytohormones decreased at the abnormal stem stage, then GA and JA kept dropping while IAA rising at the rhizome, which suggested to be the essential and key stage that inducing aerial stem-to-rhizome transition GA was presumed as the main regulation hormone with its sharp content change. The contents of soluble sugar and starch decreased throughout the development stages, when those of sucrose and fructose ascended slightly and reductive sugar ascended some quickly.