Abstract: In a process for preparing a styrenic resin, a rubber graft copolymer (A) having a weight average particle size of 0.05-0.8 .mu.m by coagulation and drying of a rubber graft copolymer latex (a). The rubber graft copolymer latex (a) is made from graft polymerization of a vinyl aromatic monomer and a vinyl cyanide monomer in the presence of a butadienic rubber latex. The styrenic resin is then prepared by a continuous bulk or solution polymerization method. The method comprises continuously charging 80 to 45 parts by weight of a vinyl aromatic monomer, 15 to 50 parts by weight of a vinyl cyanide monomer, 0 to 40 parts by weight of a copolymerizable monomer (totally 100 parts by weight of monomers), 0.1 to 6 parts by weight of the rubber graft copolymer based on 100 parts by weight of monomers and 0.