Modified electrode with a bis(salicylaldehydo)copper(II) derivatives monolayer was prepared by a two-step reaction method. At the first step, a bare gold electrode was covered with 2-aminoethanethiol (2-AET) or cystamine (CYT) by dipping into the ether/methanol solution containing 2-AET or CYT. The surfaces of the electrodes were covered with amino groups. At the second step, the 2-AET- or CYT-modified electrode was submersed into the bis(salicylaldehydo)copper(II) complex solution and the complex was fixed by reacting the amino groups with the complex under Shiff base formation. The amount of fixed complex was 2.6-3.3 x 10(-11) mol cm-2 on 2-AET-modified electrode and 5.3-5.9 x 10(-11) cm-2 on CYT-modified electrode. Differences in the amounts of fixed copper complex on the electrode will be caused by differences on the steric position and distribution of the amino groups between 2-AET- and CYT-modified electrode.