<p>Aqueous microphase-separated systems endowed with biomolecular functionalities offer a promising platform featuring mesoscopic compartments. In this study, we investigated the microphase separation of concentrated aqueous solutions of a double hydrophilic block copolymer composed of a zwitterionic polymer, poly(sulfobetaine methacrylate) (PSB4), and a glycopolymer, poly(galactose methacrylate) (PGalM), denoted as PSB4_n-<i>b</i>-PGalM_m. A series of PSB4_n-<i>b</i>-PGalM_m with varying volume fractions were synthesized through reversible addition-fragmentation chain-transfer polymerization. In dilute aqueous solutions, PSB4_n-<i>b</i>-PGalM_m formed micellar aggregates only when the PGalM block length was short. In concentrated aqueous solutions, PSB4_n-<i>b</i>-PGalM_ms that aggregated under dilute conditions exhibited disordered structures, whereas those remaining dissolved under dilute conditions yielded an ordered lattice. While the PSB4/PGalM/water ternary blends exhibited substantial compatibility under superconcentrated conditions, the corresponding PSB4_n-<i>b</i>-PGalM_m aqueous solutions underwent microphase separation. These distinctive miscibility inversions were attributed to the concentration-dependent <i>χ</i>_eff and solution-specific driving forces. Aqueous systems with periodically arranged zwitterionic and pyranose units represent a novel class of molecular assemblies resembling cell membranes, featuring arrays of zwitterions and glycocalyxes, and hold promise for the interfacial design of biomaterials.</p>