A　polymethacrylate-based　capillary　monolithic　column　with　zwitterionic　functional　groups　was　prepared　by　an　in　situ　copolymerization　method.　The　column　was　used　in　pressurized　capillary　electrochromatography　(pCEC)　for　the　separation　of　a　test　mixture　of　basic,　neutral　and　acidic　analytes.　Unique　manipulation　of　selectivity　in　pCEC　was　demonstrated　by　fine-tuning　the　applied　voltage.　The　separation　mechanism　for　neutral　compounds　was　primarily　attributed　to　hydrophilic　interaction,　whereas　the　separation　mechanism　for　charged　compounds　was　attributed　to　electrophoresis.　Due　to　the　multiple　retention　mechanisms,　the　pCEC　system　using　a　zwitterionic　monolithic　column　showed　better　separation　of　the　mixture　consisting　of　neutral　and　charged　molecules　than　capillary　liquid　chromatography　with　an　identical　column.