A number of resins (2,4DHAPDF) were synthesized by condensation of 2,4 dihydroxyacetophenone (2,4-DHA) and p-phenylenediamine (p-PD )with formaldehyde (F) in the presence of 2 M HCl as a catalyst with three different molar ratios of reacting monomers (1:1:2, 2:1:3, 3:1:4) at 1300C ±20C. Resins have been characterized by elemental analysis, infrared (IR) spectroscopy and nuclear magnetic resonance (1HNMR) spectroscopy and the morphology of the resin was examined by SEM technique. The number average molecular weight of the resin was determined by non –aqueous conductometric titration. The antimicrobial activities of the terpolymer were screened on various bacteria and fungi. All the synthetic terpolymer showed excellent antimicrobial activities with increasing molar ratios of reacting monomers.