New series of 3, 6-disubstituted-1, 2, 4-triazolo-[3, 4-b]-1,3,4-thiadiazoles (5a-j) have been synthesized by condensation of 3-aryl substituted-4-amino-5-mercapt-(4H) - 1, 2, 4-triazole (4a) with various aromatic acids in the presence of phophorus oxychloride. The structure of synthesized compound was supported by elemental analysis, IR, 1HNMR and mass spectral data. The compounds 5a-j was screened for antifungal activity against Candida albicans and Aspergillus niger and antioxidant activity by DPPH and Nitric oxide methods. Among all the synthsised products, the compounds 5d, 5f and 5h bearing hydroxy phenyl ring in 6th position of triazolo-thiadiazole exhibited significant antifungal activity with MIC value at 6.25 μg/ml. All the compounds showed moderate to good antioxidant activity by both the methods.