The objective of this research was to develop the adsorbent far heavy metals by activating the bark sample. Barks from pine tree with diameters of $2{sim}4;mm$ were activated in the muffle furnace under a high relative humidity condition at temperatures of $600{sim}900^{circ}C$. The removal efficiency of the activated bark (ACTBARK) for Cu and Cd was temperature dependent showing the order of $900^{circ}C$ > $800^{circ}C$ > $700^{circ}C$ > $600^{circ}C$. The critical temperature was considered to be $900^{circ}C$ to become an efficient adsorbent for Cu and Cd. The bark samples activated at temperatures lower than $700^{circ}C$ showed a less removal efficiency than the crude bark. The ACTBARK activated at $900^{circ}C$ removed more Cu and Cd from solution than the commercial activated carbon and charcoal. The ACTBARK (activated at $900^{circ}C$) adsorbed all of the Cu and Cd in solution with concentrations less than 150 mg/L. The selectivity of the ACTBARK was in the order of Cu > Zn > Ni > Pb > Fe > Cd > Mn.