In order to reveal the effect of xanthan gum on the performance of colloidal gas aphron（CGA）and blocking behavior characteristics of CGA，the CGA was prepared by betaine surfactant and xanthan gum solution under the condition of high speed stirring. The effect of xanthan gum concentration on the foaming ability，viscosity and bubble size was studied，the plugging effect of CGA was investigated by homogeneous and heterogeneous sandpacks. The experiment results showed that with the increase of xanthan gum concentration，the viscosity of awaiting foaming solution，low shear rate viscosity of CGA and drainage half-life increased，and foaming volume decreased. The drainage half-life and foaming volume of CGA was 46 hrs and 345 mL respectively， and its low shear rate viscosity was greater than 40 Pa·s when xanthan gum concentration was 6 g/L and surfactant concentration was 4 g/L. When xanthan gum concentration was the same，the average diameter of CGA increased with the extension of standing time. When standing time was the same，the average diameter of CGA decreased with increasing xanthan gum concentration. Diameter swelling rate of CGA slowed down with the increase of xanthan gum concentration. Micrographs showed that CGA owned a unique thick aqueous protective shell，bubbles existed in separate spheres and there was no plateau boundary around bubbles which stability was higher. CGA had a strong plugging effect toward homogeneous and heterogeneous model. The maximum displacement pressure of homogeneous and heterogeneous model reached 7.52 and 7.89 MPa respectively. CGA could remarkably improved heterogeneity of reservoir and showed a better profile control ability.