The freezing concentration of aqueos extracts feom the residual rhizome of Anoectochilus roxburghii has been investigated. The loss rate caused by entrainment of ice crystals and the rate of the freezing concentration were selected as the evaluation indexes to design the optimization of processing by the response surface methodology. The experimental results showed that the most ideal process were as the followed: the temperature difference between refrigerant and concentration 5 ℃, scraper speed 45 r/min, and freeze concentration time, 13.5 h. Under the conditions, the loss rate caused by entrainment o f ice crystals was 0.891 0% and the rate of the freeze concentration was 0.953 6 mg/(mL·h), and the comprehensive score was 0.796 1, which was the best comprehensive evaluation score in all.