Abstract: Tonka-bean was used as the raw material to make the milk, discussing the effect of heat treatment and the dosage of sucrose on the Tonka-Bean milk extent of browning. the response surface methodology was applied to optimize the boiling syrup condition. Effects of three crucial factors (boiling syrup temperature, boiling syrup time, the dosage of sucrose) on the Tonka-bean milk extent of browning were investigated adpoting one-factor-at-a-time design. Using the browning index and sensory score as index, the experiment condition were determined with three factors and there levels, according to the analysis of the variance and curved surfaces, and the optimizing of parameters of fitted mathematical model.The best condition was:boiling syrup temperature 90℃, boiling syrup time 4min, the dosage of sucrose 10%, the actual browning index was 0.07502, sensory value was 94, pretty close to predicted values, so the optimizing of heat treatment condition and the dosage of sucrose was reliable and efficient, it benefit to improve the sensory quality of Tonka-bean milk.