We have reported synthesis and vesicular assembly of a novel amphiphilic polyurethane with hydrophobic backbone and hydrophilic pendant carboxylic acid groups which were periodically grafted to the backbone via a tertiary amine group. In aqueous medium the polymer chain adopted a folded conformation which was stabilized by intrachain H-bonding among the urethane groups. Such model was supported by concentration and solvent-dependent FT-IR, powder XRD, and urea-mediated,"denaturation" experiments. Folded polymer chains further formed vesicular assembly which was probed by dynamic light scattering, TEM AFM, SEM, and fluorescence microscopic studies, and dye encapsulation experiments. pH-dependent DLS and fluorescence microscopic studies revealed stable Polymersome in entire tested PH Window of 3.5-11.0. Zeta Potential measurements showed a negatively charged surface in basic pH while a charge-neutral surface in neutral and acidic pH. MTT assay with CHO cell line indicated good cell viability.