Copolymer resin (4-MAPHF) was synthesized by the condensation of 4-methyl acetophenone (4-MA) and phenyl hydrazine (PH) with formaldehyde (F) in the presence of hydrochloric acid catalyst and using varied molar ratios of reacting monomers. Copolymer resin compositions have been determined on the basis of their elemental analysis and the number average molecular weights of resin were determined by conductometric titration in non-aqueous medium. Viscometric measurements in dimethyl formamide (DMF) have been carried out with a view to ascertain the characteristic functions and constants. The UV-visible, FTIR and proton nuclear magnetic resonance (1H NMR) spectra were studied to elucidate the structure. The surface features and crystalline behaviour of the copolymer resin have been analyzed by scanning electron microscope (SEM).