Abstract: The influence of the vacuum freeze drying conditions of kiwifruit pulp,including the pressure,thickness of frozen pulp and heating temperature,on the properties of dried kiwifruit powder,such as the vitamin-C content,drying-rate and color difference,was analytically investigated in Box-Behnken response surface design,mathematically formulated with quadratic regression model,numerically simulated in genetic algorithm and experimentally evaluated for the process optimization.Freeze-dried under the optimized conditions,including a thickness of 8 mm,a pressure of 20 Pa and a temperature of 40℃,the kiwifruit powder had a vitamin-C content of 51.75 mg/10 g,a color difference of 3.82 and a drying-rate of 1.89%/h.We suggest that the self-developed quadratic regression model be of some theoretical and technological interest in production of vacuum freeze-dried kiwifruit power on industrial scale.