Abstract: Initiated by bi-benzoyl peroxide (BPO), maleic anhydride (MAH) was grafted onto the surfaces of polypropylene (PP) beads, swelled with a small amount of toluene, at the boiling point of a self-stirring water suspension system. The influences of reaction time and the dosage of MAH and BPO on graft degree of the copolymer were investigated by orthogonal experiments. Under the chosen optimal condition of 120ml water, 10 ml toluene, 0 3g BPO, 8 0g MAH and 20 0g PP reacted through circumfluence for 4 5h at the boiling point 102℃, MAH grafted PP (MAH- g-PP ) with a graft degree 9 06% was obtained and it’s graft status was characterized by FTIR spectra. The results from a series of adsorption experiments demonstrated that MAH- g-PP showed much more affinities to polar substances like water, Cu ²⁺ , dyestuff and glucoamylase in comparison with the affinities of PP, and revealed the promise future of its wide application in solubilizers for PP alloys, ionic exchange resins, antibacterial materials, medicine carriers and enzyme supports etc. The titled method has outstanding advantages in process controls and post treatment.