Carbon nanotubes (CNTs) have been used in many materials due to their interesting properties. But CNTs do not disperse well within apolar polymer matrices such as polypropylene. Recently, polypropylene-graft-maleic anhydride (PP-g-MA) was used as a compatibilizer to improve the dispersion of CNTs within polymer. Disappointingly, the dispersion of CNTs was not expected. Here, utilizing 4-methylbenzenesulfonic acid as catalyst, PP-g-MA is chemically modified with phenol in dimethylbenzene. The resulting product (PP-g-PH) is characterized by the elemental analysis, fourier transform infrared spectra (FTIR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The dispersions of CNTs within PP-g-MA and PP-g-PH are studied.