Electropulsing at room temperature was applied to a medium carbon low alloy steel 30CrMo with varying peak voltage and current. The results showed that the pearlite colony in the specimen treated with electropulsing was smaller than that without electropulsing treatment. It was found that the lamellar structure of pearlite was refined. The grain refinement of pearlite was more obvious when the applied electric current density was higher. This may be attributed to additional free energy for the nucleation of pearlite provided by electropulsing and/or the enhancement of dislocation movement caused by electropulsing.