Activated carbon for electric double-layer capacitors was prepared from bamboos by activation with KOH solution through heating by microwave radiation. The influence of the mass ratio of KOH to bamboo, power and radiation time of microwave was studied. The behavior of charge/discharge, cyclic voltammetry and AC impedence of bamboo-based activated carbon electric double-layer capacitor was investigated. The results indicated that the specific capacitance of bamboo-based activated carbon supercapacitors can reach 277.46F/g while KOH to bamboo is 6:1 and the power and radiation time of microwave are 720W and 12 minutes respectively. Moreover, the electric double-layer capacitor using the activated carbon as electrode materials has good charge/discharge properties and cycling performance.