The　adenine,　8-hypoxanthine,　6-thioguanine　and　8-azaguanine　were　separated　and　determined　with　the　method　of　micellar　electrokinetic　capillary　chromatography.　The　optimal　conditions　of　electrophoresis　were　studied.　At　25　degrees　C　and　20　kV　applied　voltage,　the　four　components　were　baseline　separated　within　16　min　in　25　mmol/L　phosphate-borate　buffer(pH　=　7.　0)　including　30　mmol/L　SDS　at　the　detection　wavelength　of　210　nm.　The　peek　area　versus　concentration　was　linear　over　the　concentration　range　of　(12-200)　X　10(-6)　mol/L　for　8-hypoxanthine　and　8-azaguanine,　and　(6.　5-100)　X　10(-6)　mol/L　for　adenine　and　6-thioguanine.　The　detection　limits　of　all　analytes　mentioned　above　attained　to　10(-6)　mol/L　grade.　And　the　correlationg　coefficients　of　four　analytes　were　over　0.　998　5.　In　the　real　sample　of　the　mean　absolute　recoveries　of　8-hypoxanthine,　adenine,　6-thioguanine　and　8-azaguanine　were　97.　2%-102.　1%,　and　the　relative　standard　deviations　for　the　four　components　were　less　than　3.　41　%　(n　=　5).　The　method　is　rapid,　simple　with　a　good　solution　for　the　analysis　of　8-hypoxanthine,　adenine,　6-thioguanine　and　8　aza-guanine,　and　satisfactory　results　were　obtained.