Abstract: In order to provide the references for the preparation of the coal base nanocomposite, three chemical pre-treatment methods, including the ash removed method with acid, humic acid removed with alkali and air oxidization were applied to prepare the ash removed coal sample, ash and humic acid removed coal sample a nd ash removed oxidized coal sample from Shenfu coal and a study on the pore structures of each coal sample was conducted with cryogenic liquid nitrogen adsorption experiment.The results showed that the ash removing with acid, humic acid removing with alkali and air oxidized treatment would remarkably affect to the pore diameter distribution of the fine coal.After the chemical pre-treatment, the total pore volume and the specific surface area of the fine coal both would be reduced, the average por e diameter would be increased, the pore number at each pore diameter section would be reduced and the number of the micro pores would be reduced obviously.The c hemical pre-treatment process would have less influence to the pore types of the coal sample and the raw coal sample and the pre-treated coal sample were all mainly non permeability pore with one end closed .After above three chemical treatments of the Shenfu fine coal, the specific surface area and the pore volume fractal dimensio n both would be reduced, the pore structure features would be improved, the complexity of the fine coal pore system would be reduced and the fine coal would be more suitable to prepare the coal based functional composite.