A　method　using　microemulsion　electrokinetic　chromatography　(MEEKC)　coupled　with　large　volume　sample　stacking　was　developed　for　the　quantitative　analysis　of　five　compounds,　namely　liquiritin,　glycyrrhizin,　cinnamic　acid,　gallic　acid　and　protocatechuic　acid　in　Gualou　Guizhi　granules.　The　effect　of　the　microemulsion　components,　such　as　the　oil　phase,　surfactant　and　cosurfactant　on　the　resolution　of　the　analytes　was　studied.　The　baseline　separation　of　the　five　analytes　was　achieved　within　10　min　by　using　a　microemulsion　buffer　containing　0.5%　(w/v,　17　mmol　L-1)　sodium　dodecyl　sulfate,　5.0%　(v/v)　butan-1-ol,　0.5%　(v/v)　ethyl　acetate　and　94.5%　(v/v)　5　mmol　L-1　borate-10　mmol　L-1　phosphate　buffer　(pH　9.0).　After　combining　with　on-line　preconcentration　via　large　volume　sample　stacking　(LVSS),　the　detection　limits　(defined　as　S/N　=　3)　for　the　analytes　could　be　as　low　as　0.05　μg　mL-1.　MEEKC-LVSS　was　successfully　applied　to　the　determination　of　four　analytes　in　Gualou　Guizhi　granules;　the　recoveries　ranged　from　94.51%　to　97.53%,　and　good　reproducibilities　were　obtained　with　relative　standard　deviations　(RSDs)　less　than　5%.　©　2015　The　Royal　Society　of　Chemistry.