Abstract: This paper discussed the theory of adsorption at solid/liquid interfaces and the mechanism and influencing factors of adsorption and retention.Then method of analyzing the concentration of displacement agents was established in order to evaluate the adsorbance. Based on this, we determined the adsorbance of displacement agents on the condition of oil layer in Suizhong oilfield by the experiments of adsorption. In the static adsorption experiment, when the hydrophobically associating polymer was adsorbed by well core sand, their adsorbance was determined. At last, we worked out 4 adsorption curves and analyzed the characteristics of the curves. The experiment shows it is closer to the saturation when the density of the polymer reaches 700mg/g and the solid/liquid ratio is 5 ml/g. The adsorption reaches the saturation when the polymer absorption time is 18h. The absorption amount of the polymer on the net sand is greater than the oil sand.