[Objective] To study anti tumor constituents of Centipeda minima.[Method] Column chromatography and reverse phase HPLC were used for separation and purification,NMR was used to identify the structure and MTT anti tumor experiment was conducted.[Result] Dihydrohelenalin,Helenalin,Brevilin-A,Arnicolide C and Arnicolide D were identified from Centipeda minima,all of them have a certain anti tumor cell activity.[Conclusion] Five compounds have a certain inhibition effect on growth of tumor cells.