Abstract: The distribution of second phase particles in conventional grain-oriented electrical steels during manufacturing processes with MnS as inhibitors was observed by field emission scanning electron microscopy,while the areal particle density,the average particle size and the corresponding size distribution were statistically determined.It is indicated that hot rolling leads to dispersive precipitation of a large amount of fine second phase particles and the matrix keeps a supersaturated state further.Certain dissolution behaviors of second phase particles can be induced by cold rolling,in which the supersaturated state may reduce the dissolution.The precipitation nucleation of new particles and the coarsening of the particles coexist during the intermediate annealing and decarburizing annealing processes,after which the second-phase particles experience predominately the coarsening process during the final temperature rising stage of secondary recrystallization annealing.