A high strength low alloy wear-resistant steel was quenched at 900°C and tempered at varying temperatures. The microstructures were observed utilizing optical and electron microscope. Results show that microstructures consist of predominantly martensite and lots of bainite in the as-quenched specimens. When the specimen was tempered at 250°C, no obvious change in the microstructure was observed. It has an optimized strength and elongation in this condition of heat treatment. With the increase of tempering temperature, the lath or plate of martensite were coalescenced. The strength of the steel is thus greatly reduced and the elongation was accordingly increased.