By using the solution casting technique, blends of polystyrene and rosin (PS/rosin) plasticized by dibutyl phthalate (DBP) were created with various rosin content (5, 10, 20, and 30%). These blends were then exposed to various gamma radiation dosages (50, 100, 150, and 200 kGy). Scanner transform infrared spectroscopy, scanning electron microscopy (SEM), and mechanical characteristics were used to analyse the mixes (PS/rosin). FTIR and SEM were used to demonstrate the two polymers' physical miscibility. TGA is used to study thermal properties. The TGA thermograms demonstrated that as the PS component ratio in the blend is increased, the thermal stability of the unirradiated polymer blends (PS/rosin) also increases. Additionally, it was shown that the PS polymer provides protection against radiation degradation and enhances their thermal stability additionally, it was determined that adding PS to rosin improved its tensile strength and other mechanical qualities. On the other hand, by increasing the proportion of rosin in the blend, elongation was reduced.