(PP-g-DMAEMA)-g-NIPAAm was synthesized using gamma radiation from a Co-60 source. Graft polymerization of N,N'-dimethylaminoethylmethacrylate (DMAEMA) onto polypropylene (PP) was accomplished in about 100 percent yield by the mutual irradiation technique at a dose of 10 kGy. Grafting of N-isopropylacrylamide (NIPAAm) onto PP-g-DMAEMA was carried out by the pre-irradiation method with doses from 20 to 100 kGy. The influence of temperature, reaction time, and monomer concentration on grafting yield was studied. Grafting processes were confirmed by infrared spectroscopy (FTIR-ATR). (PP-g-DMAEMA)-g-NIPAAm films were characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The lower critical solution temperature (LCST) and critical pH point of the films were obtained by water contact angle and percent swelling measurements. The LCST was also determined by DSC. We report here hare a new binary graft copolymer which shows two LCST values, synthesized in two steps.