Abstract: A process for producing a styrenic resin with a small content of low molecular weight components, comprising a continuous anionic polymerization process wherein a raw material system having the following composition (A) is continuously fed, either collectively or in a divided manner, from one end of a reactor tank R1 having a back mixing flow and the product system is continuously discharged from the other end of the reactor tank R1, the internal temperature of the reactor tank R1 being controlled to a range of 40-120° C., the average proportion of styrene monomers to the sum total of the styrene monomers, hydrocarbon solvent and styrenic polymers present in the reactor tank R1 being controlled to less than 10 wt. %, and the resulting styrenic polymer solution being devolatilized and dried: (A) Styrene monomer 1.0 kg Hydrocarbon solvent 0.1-3 kg Organolithium compound 0.5-200 mmoles.