Abstract: ：In order to reduce the production cost of fuel and reduce the consumption of fuel oil，conversion of coal to liquid fuel was studied as early as in the 1980s. Coal oil mixture (COM) and coal water mixture (CWM) are two practical methods. Because CWM has a low heating value and is difficult to ignite，COM fuel is mainly used. The key to making COM fuel is development of stabilizer. A copolymer of maleic anhydride and butyl acrylate was as stabilizer of COM fuel in this study. When molar rate of maleic anhydride and butyl acrylate was 1∶5 and using pyridine as neutralizing agent，the time for a glass rod to fall from top to bottom in a graduated cylinder is still less than two seconds after the prepared COM fuel was kept for three weeks. The maximum coal loading of 59.4% in COM can be reached. Because the quantity of stabilizer added in COM fuel is small，COM fuel using this stabilizer is low cost and has good future in application.