OBJECTIVE To study the washing effect of different methods to keep the surgical instruments moist. METHODS The instruments which were selected from the routine surgical instruments within a week were washed after three different methods to keep moist. The washing effect was compared by eyes, without equipment and with 5 times magnifying glass. RESULTS The multienzymatic detergent was the best one to keep moist, the next was the water, and the chlorine releasing agent was the worst. CONCLUSIONS Hospitals should select the suitable method to keep moist by considering the actuality.