AIM: To investigate inhibition of extract from mulberry leaves on tyrosinase activity so as to provide experimental evidence for preventing and treating the disease of pigmentation. METHODS: Inhibition of kojic acid with different concentration on tyrosinase activity was measured. The control group was selected according to the positive results of inhibition rate (IR%= tyrosinase activity%)Regression equation was based using concentration of extract from mulberry leaves as independent variable and inhibition rate of independent variable on tyrosinase activity as dependent variable. The correlation between the extract from mulberry leaves and the inhibition rate was determined. RESULTS: The inhibition rates of kojic acid at 13, 14 and 15 mg/L on tyrosinase activity were 24.7%, 71.89%, 85.74%respectively, and the concentration of kojic acid was 13.65 mg/L when the inhibition rate was 50%. The inhibition rates of extract from mulberry leaves at 2.3, 4.7, 7, 9.3 and 11.7 g/L on tyrosinase activity were 24.49%,38.22%, 51.95%, 74.83%, 79.41%respectively, and the concentration of kojic acid was 6.4 g/L when the inhibition rate was 50%. Positive correlation was found between the concentration of extract from mulberry leaves and its inhibition for tyrosinase activity (r=0.985 5,P< 0.05). CONCLUSION: The inhibition of extract from mulberry leaves on tyrosinase activity is similar to that of kojic acid.