Abstract: Based on the basic principle of chemical etching, using water bath controlled in both temperature and time, in combination with optical microscope, a method was investigated to reveal austenite grain boundaries of quenched 1.79Al-1.5Mn-1.09Cr high aluminum complex alloy steels. The results show that the chemical etching method at room temperature using 30 mL supersaturated picric solution, one or two drops of hydrochloric acid and moderate Seagull brand paste shampoo could clearly reveal the austenite grain boundaries of the quenched steels, and the amount of Seagull brand shampoo should be adjusted according to the heating temperatures for quenching. The higher the quenching temperature, the easier the revealing of austenite grain boundaries was.