A　novel　tentacle-type　polymer　stationary　phase　covalently　modified　with　branched　polyethyleneimine　(PEI)　was　developed　for　peptides　and　proteins　separations　by　open-tubular　CEC　(OT-CEC).　The　preparation　procedure　included　the　silanization　of　capillary　inner　wall,　in　situ　graft　polymerization　and　PEI　functionalization.　A　wrinkly　polymer　surface　of　multitudinous　steric　amine　groups　was　evenly　formed　on　the　capillary　inner　wall,　and　anodic　EOF　could　be　gained　within　a　wide　pH　range　of　2.5-7.5.　The　electroosmotic　mobility　was　examined　for　its　dependence　on　pH　as　well　as　PEI　concentrations.　Good　repeatability　was　gained　with　RSD　for　the　migration　time　of　EOF　marker　within　4.8%　and　satisfactory　chemical　stability　was　validated.　Due　to　the　existence　of　amine　groups　on　the　surface　of　tentacle-type　polymer　stationary　phase,　the　silanol　effect　that　occurs　between　the　positively　charged　biomolecules　and　the　silanols　of　the　capillary　column　was　greatly　suppressed.　Compared　with　a　monolayer-coating　capillary,　seven　enkephalin-related　peptides　were　well　resolved　on　the　PEI-bonded　column　with　high　efficiencies.　Favorable　separations　of　peptides　and　proteins　with　high　column　efficiencies　were　obtained　in　144　000-189　000　and　97　000-170　000　plates/m.　Branched　PEI-bonded　tentacle-type　polymer　stationary　phase　has　been　proven　to　afford　satisfactory　retention　and　resolution　of　peptides　and　proteins.　Copyright　©　2011　WILEY-VCH　Verlag　GmbH　&　Co.　KGaA,　Weinheim.