A new series of 1,4-bis[5-(5-mercapto-1,3,4-oxadiazol-2-yl-methyl)-thio-4-substituted-1,2,4-triazol-3-yl]-butane 7-12 and 1,4-bis[5-(1-oxo-1-(3,5 dimethyl pyrazol-1-yl)-methyl)-thio-4-substitued-1,2,4-triazol-3-yl]-butane 13-18 were prepared from 1,4-bis(5[hydrazinocarbonylmethylthio]-4-substituted-1,2,4-triazol-3-yl) butane based derivativess were synthesized 1-6. All the synthesized compounds were characterized by IR, NMR and Mass spectral studies. The synthesized compounds 7-18 were screened for in-vitro cytotoxicity potential using the standard MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay against a panel of three human cancer cell lines: Lung carcinoma A-549, colon carcinoma HT-29 and breast cancer MDA MB-231. DNA binding studies were conducted for three potent molecules by absorption titration method.