Kilgore's colorimetric method has been modified for the determination of 2-(1-Mehylheptyl)-4,6-dinitrophenyl crotonate (abbr. DPC) residues in cucumber. The residue is suitably extracted with n-hexane and purified by washing with sulfuric acid. Result of washing experiment has shown the residues are easily removed by tap water washing. Recovery experiments (table 2) and residue data (table 3) are also presented.