AIM: To study the reactions of human platelet to active complement and the effects of anti-CD59 on human platelet activation induced by complement. METHODS: By applying CVF to activate complement, the platelet aggregation and release reactions induced by activated complement with or without appling anti-CD59 with different doses to block the complement modulative protein CD59 in healthy individuals, were observed. RESULTS: CVF induced platelet release and significant and lasting metamorphosis in healthy individuals, but platelet aggregation was not observed. CVF-induced platelet metamorphosis showed positive linear correlation to lg concentration of CVF (r=0 970. P