Abstract: Char samples were prepared by pyrolysis of oily sludge and blended coal at 850-1150 ℃. The pore structure and crystallite structure of chars were analyzed by N₂ adsorption-desorption and X-ray diffraction (XRD). Effects of pyrolysis temperature and amount of oily sludge on gasification reactivity of the char was investigated by thermogravimetric analysis (TGA). The results show that increasing pyrolysis temperature and adding oily sludge can promote the formation of more abundant pore structure of chars, strengthen chars-CO₂ gasification reaction and inhibit graphitization process of chars, thus improving gasification reactivity of the chars. However, too high pyrolysis temperature or too much sludge will also result in dense structure or pore plugging of coal char, and reduce gasification reactivity of the char.