An atomic force microscopy (AFM) has been applied to study the adsorption of collectors on chalcopyrite surface in aqueous solutions. AFM images showed that collectors absorbed on mineral surface in patches after the chalcopyrite sample was soaked in potassium ethyl xanthate (KEX) or potassium amyl xanthate (PAX) solutions at pH 11. At the same time, as shown by the obtained AFM force curves, the adhesion between the AFM tip and the substrate increased greatly due to the collector adsorption. Rinsing with ethanol removed the patch-like absorbate instantly from the chalcopyrite surface. Patch-like absorbate was also observed on chalcopyrite surface in the solutions of two industrial collectors, i.e., Col-1 and Col-2. The potential impact of this patches adsorption on chalcopyrite flotation is discussed.