Three acrylpimaric acid polyglycol esters (APAPG) with different molecular weight were successfully prepared. The surface properties of three esters were investigated by surface tension and fluorescence techniques. The critical micelle concentrations (CMC) were detected. Reorientation theory was proposed to describe the adsorption behavior and the conformational changes of these surfactant molecules at the air-water interface. With increasing ester concentration the molar fraction of solvent decreased and that of surfactant molecules increased. The adsorption amount of state 1 presented unimodal shape and adsorption amount of state 2 presented sigmoid with the growth of.. The free energy of adsorption is more negative than that of micellization, thus the surfactant molecules adsorb on the surface firstly and then form micelles after saturation adsorption. (C) 2017 Elsevier Ltd. All rights reserved.