The effect of the heat treatment process parameters on the mechanical properties and microstructure of SWRS82B wire rods were investigated. Specimens were austenitized at 850°C~900°C and held at 500°C~600°C. The results show that the interlamellar spacing and the pearlite block size become finer with the decrease of the isothermal temperature. At the same isothermal temperature condition, the interlamellar spacing decreases with the increase of austenitizing temperature. The fine interlamellar spacing increases the yield strength and ultimate tensile strength.