Developing an efficient approach of transforming biomass waste to functional carbon-based electrode materials applied in supercapacitor offers an important and high value-added practical application due to the abundance and considerable low price of biomass wastes.Herein,a hierarchical carbon functionalized with electrochemical-active oxygen-containing groups was fabricated by microwave treatment from the biomass waste of camellia oleifera.The obtained mesoporous carbon (MAC) owns nanosheet morphology,rich mesoporosity,large surface area (1726 m2/g) and very high oxygenic functionalities (16.2 wt％) with pseudocapacitive activity.Prepared electrode of supercapacitor and tested in 2.0M H2SO4,the MAC exhibits an obvious pseudocapacitive activity and achieved a superior supercapacitive performance to that of directly activated carbon (DAC-800) including high specific capacitance (367 F/g vs.298 F/g) and better rate performance (66％ vs.44％).The symmetrical supercapacitor based on MAC shows a high capacity of 275 F/g,large energy density of 9.55Wh/kg (at power density of 478W/kg) and excellent cycling stability with 99％ capacitance retention after 10000 continuous charge-discharge,endowing the obtained MAC a promising functional material for electrochemical energy storage.