To provide the chemical data for resources development of Stephania mashanica,its chemical constituents were investigated; Method: The powered tuber of S. mashanica were extracted with 2% H2SO4-H2O and purified by silica gel, alumina oxide and Sephadex LH-20 column chromatograph. The structures were elucidated on the basis of spectral analysis and physico-chemical evidence. Result: Seven alkaloids were isolated from the thin sulfuric acid extracts of the fresh roots of Stephania mashanica, these alkaloids were identified as dicentrine (1), (() -crebanine (2), sinoacutine (3), tetrahydrocolumbamine (4), tetrahydropalmatine (5), palmatine (6), and jatrorrhizine (7). Conclusion: compounds 2-7 were obtained from this plant for the first time.