1. Crebanine iv 5mg/kg can eonvert BaCl_2-induced arrhythmia into sinus rhythm in rats, and can significantly increase the tolerant dose of aconitine to produce ventrieular fibrillation(VF) and cardiac arrest (CA) in rata. 2. Crebanine can also decrease the incidence of VF and CA by CaCl_2 in rats and by chloroform in mice, but has no proteetive effects on ouahain-indueed arrhythmias in guinea pigs. 3. Crebanine has potential utility of crebanine in the development of neurodegenerative therapy, might be used as the starting point to develop a drug for Alzheimer's disease. 4. Crebanine has anti-cancer activity, can inhibit the proliferation of human leukemic cells (HL-6, U937 and K562), human fibrosarcoma cells (HT18) and cervix cancer cell lines (KB-3-1 and KB-V1; it mediates cell cycle arrest at G/G1 phase and this was associated with down-regulation of cyclins A and D.