Amide-functionalized humic acids (AHA) was synthetized by two step reactions, in which humic acids first reacted with thionyl chloride(SOCl2) and then reacted with ammonia liquor. The AHA was characterized by Fourier transform infrared (FTIR) spectra and elemental analysis method. The reaction properties between AHA and mercury ions(I,II) were investigated at an AHA chemically modified carbon paste electrode (AHACMCPE) using cyclic voltammetry (CV) and linear sweep stripping voltammetry (LSSV). Moreover, the binding behavior of numerous other ions at the AHA-CMCPE was also tested. In an open circuit, Both HgI and HgII were accumulated from a stirred 0.1M H2SO4 solution onto the AHACMCPE. The subsequent electrochemical measurement was performed in another clean supporting electrolyte of 0.5M H2SO4. Factors affecting the accumulation and electrode reaction steps were investigated and an optimized procedure for quantifying mercury was developed. Under optimized conditions, a calibration plot for mercury concentration in the range 4.98