Infrared spectral analysis technology has become one of the most important research techniques in the field of action mechanism of flotation reagents. Due to the high adsorptivity of mineral, it is difficult to detect the weak signal of adsorbed reagents on mineral surface by traditional transmission infrared KBr disc spectroscopy. In this study, the adsorption form and morphology of oleate on collophane surface were measured by microscopic reflectance infrared Fourier transform at various oleate concentrations. We found that the reflectance infrared spectroscopy had greater sensitivity for adsorbed oleate species on surface when being compared with transmission infrared technique, which was more suitable to reveal the adsorption mechanism at normal flotation concentrations of oleate. The results showed that the chemisorbed oleate at a single peak of 1 552 cm-1 and calcium oleate precipitate physically adsorbed at doublet peaks of 1 570 and 1 535 cm-1 coexisted on the collophane surface at lower oleate concentration under alkaline condition. In addition, when the oleate concentration was over critical micelle concentration, the collophane surface became hydrophilic due to the adsorption of oleate micelles, which made sodium oleate solution leave on the surface, so the above peaks were covered by the sodium oleate peak of 1 560 cm-1. What’s more, the peak intensity of adsorbed oleate sharply decreased after being washed with deionized water, because the residual sodium oleate and calcium oleate precipitate physically adsorbed could be rinsed. Besides, according to the two-dimensional micrographs, with the increase of sodium oleate concentration the adsorbed oleate aggregated into the laminated structure from a dot structure, and its coverage enlarged but it was not a complete coverage. This was attributed to the surface heterogeneity. These could provide a better understanding of the interaction mechanism between oleate and collophane in the flotation of phosphate ores and high-phosphorus iron ores.