Murraya　paniculata　(L.)　is　a　traditional　Chinese　medicine　(TCM)　wildly　grown　in　southeast　China,　and　used　for　abortion　in　folk.　Murrayone,　a　coumarin-containing　compound　extracted　from　M.　paniculata,　is　the　most　bioactive　substance　in　this　species　and　is　being　developed　as　a　novel　cancer　metastasis　chemopreventive　agent　based　on　its　unique　pharmacological　properties.　In　the　present　study,　a　novel　rapid　and　sensitive　method　for　quantitative　analysis　of　murrayone　in　rat　plasma　and　for　determining　its　pharmacokinetics　in　rats　was　developed　and　validated　using　UPLC/MS/MS.　Plasma　samples　were　subjected　to　protein　precipitation　and　then　directly　analyzed　by　UPLC/MS/MS.　Both　murrayone　and　coumarin　as　an　internal　standard　(I.S.)　were　carried　on　a　C18　column　with　a　gradient　mobile　phase　consisting　of　acetonitrile　and　water　at　a　flow　rate　of　0.3　mL/min.　Several　gradient　elution　procedures　were　evaluated　to　achieve　effective　chromatography　resolution　and　a　sensitive　response　to　murrayone　and　the　I.S.　Mass　spectrometry　was　carried　out　using　a　triple-quadrupole　system　via　positive　electrospray　ionization　and　multiple　reaction　monitoring　(MRM).　Good　linearity　(r　2　=　0.9987)　was　achieved　over　a　linear　range　of　4.0–1600　ng/mL　with　a　lower　limit　of　quantitation　(LLOQ)　of　4.0　ng/mL　for　murrayone.　The　inter-　and　intraday　accuracy　and　precision　ranged　from　90.0　to　99.7%　and　1.1　to　12.3%　at　four　quality　control　concentrations,　respectively.　The　average　absolute　recoveries　of　murrayone　and　the　I.S.　were　determined　to　be　85.9–92.4%　and　86.5–90.7%,　respectively,　at　10.0,　80.0,　and　800　ng/mL.　Murrayone　was　stable　under　a　variety　of　storage　and　processing　conditions　that　may　be　routinely　encountered　in　laboratories　based　on　all　the　stability　tests.　This　newly　developed　method　was　successfully　applied　to　the　pharmacokinetic　study　of　murrayone　in　rats　for　the　first　time,　and　the　current　assay　methodology　could　provide　important　insights　into　potential　therapeutics　and　facilitate　further　pharmacodynamic　explorations　of　murrayone.　©　2019