Abstract: Four alkaloids were isolated from the root of Stephania epigeae H. S. Lo (Menispermaceae) and identified as cycleanine (Ⅰ), cepharanthine (Ⅱ), 1-curine (Ⅲ), and isocorydine(Ⅳ), respectively by chemical studies and spectral analysis.This is the first time that 1-curine was fonnd in the stephania plants.Cepharanthine possesses preventive and curative effect on leucopenia induced by Xray or chemical substances, it holds promise as a radioprotective agent. It is shown also that the dimethiodides of (Ⅰ), (Ⅲ) were muscle relaxants. The potency of (Ⅲ)is similar to that of d-tubocuraine, whereas 0, 0-dimethylcurine methiodide is three times more potent than the parent dimethiodide. (Ⅰ) also has curative effect on experimental silicosis in rats.