A　new　method　of　online　concentration　capillary　electrochromatography　using　a　lauryl　methacrylate-based　monolithic　column　was　developed　for　determination　of　three　beta　2-agonists　including　salbutamol,　procaterol,　and　formoterol.　The　separation　parameters　including　acetonitrile　concentration,　running　buffer　pH,　and　concentration　were　evaluated.　To　improve　the　sensitivity,　an　online　concentration　method　with　combination　of　the　chromatographic　zone-sharpening　effect　and　field-enhanced　sample-stacking　effect　has　been　developed　in　which　the　concentration　parameters　including　injection　voltage,　injection　time,　as　well　as　sample　matrix　were　systematically　studied.　Under　the　optimized　conditions,　baseline　separation　of　three　beta　2-agonists　was　achieved　within　4　min.　When　compared　to　the　conventional　sample　injection,　this　online　concentration　technique　increased　their　corresponding　sensitivities　up　to　45-,　36-,　and　320-fold,　respectively.　Furthermore,　good　repeatability　was　obtained　with　relative　standard　deviations　(RSDs)　for　migration　times　within　0.84%　and　those　for　peak　areas　less　than　6.35%　(n　=　5)　in　the　experiment.　The　proposed　method　was　successfully　applied　to　the　determination　of　above-mentioned　beta　2-agonists　in　urine　sample.　The　recoveries　of　spiked　urine　samples　were　between　82.4%　and　109.1%　with　RSDs　less　than　9.97%.