The main objective of the present study is to investigate the efficiency of microwave to extract the polysaccharide from soy bean hull. Plackett–Burman design was used to screen the effective process variables among weight of the sample (g), concentration of NaOH (%), microwave power (W), agitation speed (rpm), extraction time (min), temperature (°C) and volume of solvent (ml). Box-Behnken design (BBD) was used to study the individual and interactive of process variables on the polysaccharide yield. Optimum conditions for maximizing the polysaccharide yield was determined using Derringer’s desired function methodology as follows: Sample weight of 3 g, microwave power of 300 W, extraction time of 5 min and temperature of 45°C. Under these optimal conditions, predicted polysaccharide yield was found to be 27%. Fourier transform infrared spectroscopy (FTIR) was used to obtain vibrational spectra and the results indicated the presence of polysaccharide. This result confirms the effectiveness of microwave to extract the polysaccharide from soy bean hull.