Bamboo-carbon was modified with ZnCl2 by microwave radiation to enhance its adsorption capacity, the optimum technology was obtained through orthogonal test, and the kinetics and mechanism of adsorption of 4-Nitrophenol by modified bamboo-carbon were studied. The results showed that the optimum conditions were as follows: ratio of ZnCl2 solution to bamboo-carbon is 2.0 to 1.0, concentration of ZnCl2 solution50% and impregnating time 8 hours, microwave power 800 watts, radiation time 6 minutes. Compared with bamboo-carbon, the specific surface areas, total pore volume and the adsorption efficiency of 4-nitrophenol of modified bamboo-carbon were increased obviously. The adsorption processes follow a pseudo second-order kinetic rate equation and their linear correlation coefficients could be over 0.999. Intra-particle diffusion was not the rate-controlling step. The adsorption of 4-nitrophenol by modified bamboo-carbon, which was an endothermic process. has a small energy of activation, and was mainly a physical adsorption process.