A high sensitive and selective imprinted electrochemical sensor based on cobalt nanoparticles/gra-phene modified carbon electrode was prepared by electropolymerization technqiue with p-tert-octylphenol as the template and pyrrole as the functional monomer. The electrochemical behaviors of the imprinted sensor were evaluated with cyclic voltammetry and differential pulse voltammetry. The response currents of the imprinted electrochemical sensor exhibited a linear relationship toward the negative logarithm of p-tert-octylphenol concentrations ranged from 1. 0í10-13 mol/L to 1. 0í10-7 mol/L (R2=0. 994) with the detection limit of 3 . 7í10-14 mol/L ( S/N=3 ) . The imprinted electrochemical sensor was respectively applied to the determina-tion of p-tert-octylphenol in rain water, lake water and drink with the recoveries of 92. 4%-102. 0%.