Three complexants, maleic acid, sodium citrate and sodium salicylate, were used to modify the activated carbon, using the activated carbon without modification for comparison. And the effects of the complexants on the performance of Pd/C catalysts used for the disproportionation of rosin were analyzed by FTIR，XRD, XPS, and TEM. The results show that the chelating agents deposited on activated carbon have a strong bonding ability with Pd cation, which is beneficial to form a smaller Pd particle, enhancing the utilization ratio of Pd. So the activity of Pd/C catalyst prepared with the modified activated carbon was significantly higher than that of untreated activated carbon.