Carbon nanotubes have a high electrochemically accessible area of porous tubes, good electronic conductance and strong mechanical property. These properties essentially suggest that CNTs are attractive materials for the construction of nanoscaled biosensors. Ligand frameworks such as the Schiff base containing salen ligand, that can be sterically and electronically modified with ease, are very attractive. The use of the salen ligand framework in catalytic reactions has been receiving increasing interest because of its success in many newly discovered processes. In this paper, MWCNTs and Zn-salen were alternative deposited onto the surface of glassy carbon electrode via layer-by-layer assembly technology. We find that (MWCNTs/Zn-salen)n multilayer films have excellent electrocatalytic activity for L-tyrosine and NO2-. Hence, a nanostructured electrochemical sensor for simultaneous detection L-tyrosine and NO2- was developed successfully.