A　novel　zwitterionic　monolith　was　prepared　by　in　situ　covalent　attachment　of　glycin　to　a　gamma-glycidoxypropyltrimethoxysilane-modified　silica　monolith.　The　monolith　possessing　in　its　structure　bonded　secondary　amine　groups　and　carboxylic　acid　groups　was　evaluated　in　pressurized　CEC　(pCEC)　system　using　small　neutral　and　charged　solutes.　Owing　to　the　zwitterionic　nature　of　the　resulting　stationary　phase,　the　direction　and　magnitude　of　EOF　in　this　column　could　be　manipulated　by　adjusting　the　pH　values　of　the　mobile　phase.　Typical　hydrophilic　interaction　was　observed　when　the　ACN　content　exceeded　45%.　Separations　of　acidic　and　basic　compounds　were　performed　on　the　prepared　column　in　weakly　anodic　and　cathodic　EOF　modes,　respectively.　The　organic　solvent　composition,　the　salt　concentration,　and　the　pH　of　the　mobile　phase　have　effects　on　the　electrochromatographic　retention.　Besides　the　hydrophilic　interaction　and　electrophoretic　mechanism,　electrostatic　interactions　are　also　involved　in　the　separations　of　acids　and　bases　on　the　zwitterionic　column.