Abstract: A dispersion of Au nano-particles (AuNPs) and multiwalled carbon nanotubes (MWCNTs) was prepared and dropped onto the surface of the pretreated glassy carbon electrode to prepare GCE modified with the composite nanomaterial, abbr. as AuNPs/MWCNTs/GCE. Electrochemical behavior of 2,4-dinitrophenol (2,4-DNP) at the modified electrode was studied by CV. It was shown that electrocatalytic action toward 2,4-DNP was observed by the modified electrode. A pair of redox peak was observed at the potentials of (Epa) 0.183 V and (Epc) 0.125 V. Under the optimum conditions, linear relationship was kept between values of oxidation peak current (ipa) and concentration of 2,4-DNP in the range of 5.0×10-6-4.0×10-4mol·L-1. Based on these facts, a method of LSV for direct determination of 2,4-DNP in water was proposed. Recovery was tested by standard addition method, giving results of recovery in the range of 94.0% to 104% with RSD′s (n=6) in the range of 2.0% to 3.0%.