The integral membrane protein CD40 was found on the surface of B lymphocytes that interact with CD40L on T cells during the immune response. The hydrophobic transmembrane domains of membrane proteins can be stabilized in detergent or in lipid bilayers such as liposomes. Membrane proteins can be incorporated into the liposome in a similar fashion to the way they are handled in vivo. In this study, a large amount of full-sequence CD40 was produced using a bacterial system that contained a Mistic construct. The CD40 was then reconstituted into liposomes by detergent-mediated reconstitution. All stages in the process of liposome disruption with various detergent ratios were easily observed by monitoring the optical density. The structure of the liposome and the reconstitution of CD40 were confirmed by cryo-TEM. The results of the present study show that the detergent ratio had an effect on the structure of the liposome and the amount of CD40 that was reconstituted into the liposome.