Wood tar is the pyrolysis product of woody biomass materials. In this study, wood tar was used as carbon source and wood tar treated by formaldehyde was used as precursor to prepare activated carbon by carbonization and activation. The adsorption of methylene blue in the simulated water was investigated by using wood tar based activated carbon as adsorbent. The results show that the porous activated carbon prepared by carbonization and activation at high temperature with wood tar as precursor has a specific surface area of 1373 m2?g-1 and rich oxygen-containing functional groups on the surface ,the quasi-second-order kinetic model more accurately described the adsorption kinetics of methylene blue on activated carbon derived from wood tar, and the adsorption isotherms of methylene blue on activated carbon derived from wood tar are more consistent with Langmuir adsorption isotherm model. The maximum adsorption capacity of methylene blue on activated carbon derived from wood tar was 559 mg?g-1. Thermodynamic analysis shows that the adsorption of methylene blue on activated carbon is exothermic and spontaneous. The activated carbon prepared from wood tar has potential application prospect with the excellent adsorption capacity for methylene blue.