An evidence of tethered lipid bilayer formation by vesicle adsorption onto lipopolymer monolayers is studied using atomic force microscopy (AFM). Polymer hydration is found to be an important factor governing this process. It is found that hypotonic osmotic stress acting upon lipid vesicles stimulates their incorporation in homogeneous bilayers on polymeric substrates. The formation of multilamellar and more complex surface aggregates is prevented. The polymer-supported lipid membrane is indeed a thermodynamically stable structure which can self-organize after lipid is supplied to a polymer-supported monolayer in hydrophilic and saline environment.