Aim To improve anti free radical activities of some cardiovascular and tubercular medicines,structure modification were made so as to attain double functions as medicines and free radical scavengers.Methods Diphenylmethyl piperazine and caffeic acid,catechualyehyde and p aminosalicylic acid were taken as materials respectively to synthesize (E) 1 diphenylmethyl 4 <3 (3,4 dihydroxy phenyl) 2 propenyl> piperazine(I) and Schiff base N catechualyehyde p aminosalicylic acid(Ⅱ).At the same time,scavenging O 2 ·- free radical activities were detected through Xanthine-Xanthine Oxidase Luminol Chemiluminescence system.Results Through elementary analysis and the detection of IR and 'H NMR spectra,results indicated the two new compounds could accord with its constitution.The 50 values of SOD-like actiuities of solution(I) and solution(Ⅱ) determined by chemiluminesceme were 756 nmol·L -1 and 745nmol·L -1 respectively.Conclusion The two new compounds not only reserve effective structure position of original medicines,but also have strong anti free radical roles.