Abstract: In order to establish a simple and effective processing method to reduce the bitterness of Bletilla striata (Thunb. ex A. Murray) Rchb.f., response surface methodology was used to explore the best optimum conditions of hot water rinsing B. striata fresh stem slices. Taking the content of 1,4-bis［4-(glucoseoxy) benzyl］-2-isobutyl malate(militarine) as the index the effects of hot water rinsing temperature, rinsing time and pH value on the militarine content in B. striata were investigated by a single factor experiment, and the rinsing was optimized by Box-Behnken response surface analysis. The optimum conditions were obtained as follows: rinsing temperature of 95 ℃, rinsing time of 50 min, hot water pH of 6.5.Under these optimized conditions, the mass fraction of militarine decreased by 63.55% in parallel experiments, and the mass fraction of militarine in the fresh stem slices of B. striata reduced 83.10% after three rinses. Rinsing B. striata fresh stem slices with hot water for 1-3 times could significantly reduce the content of militarine under optimum conditions.