Response surface method (RSM) was employed to optimize the extraction conditions of polysaccharides from Rhizoma Panacis Majoris (the rhizomes of Panax japonicas C. A. Mey. var. major (Burk.) C. Y. Wu et K. M. Feng) (RPMP), a well-known Chinese traditional medicine. In order to obtain the optimal processing parameters, a three-variable Box-Behnken designs (BBD) were applied for experimental designs. RSM analysis indicated the good correspondence between experimental and predicted values, the optimal conditions for the yield of polysaccharides were as follows: the ultrasound time is 31.15 min, ...