Abstract: In this paper,the acid-functionalized multi-wall carbon nanotubes/porous carbon (AMWCNTs/PC) composites were prepared by an effective method,and the application of the composites for electrochemical energy storage was also studied. In the synthesis,the AMWCNTs were mixed with cyclodextrin by a milling method. The acid treatment was favorable for the formation of a uniform and effective composite due to the enhancement of the interaction of AMWCNTs with cyclodextrin. After carbonization under N₂ protection and activation with ZnCl₂,the AMWCNTs/PC composites could be obtained. The materials were characterized by transmission electron microscopy,X-ray diffraction and Raman spectroscopy. The results indicate that the CNTs are uniformly distributed into the framework of the porous carbon,and the materials have a high BET specific surface area and good conductivity. Cyclic voltammetry(CV) and galvanostatic charge-discharge(GCD) measurements indicate that the composites have good performances for electrochemical energy storage and a high stability. The AMWCNTs/PC-12-4(numbers 12 and 4 represent the mass ratios of cyclodextrin to AMWCNTs and AMWCNTs/PC to ZnCl₂,respectively) exhibits a high specific capacitance of 156 F/g,much higher than the AMWCNTs(43 F/g) and PC-4(87 F/g) at 0.5 A/g. Also,the AMWCNTs/PC-12-4 shows superior cycle durability and columbic efficiency over 99.9% after 5000 cycles in KOH,indicating a promising potential for AMWCNTs/PC-12-4 to be used as electrodes materials in supercapacitor.