A selective and sensitive ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for the determination of ziyuglycoside I (I), 3β,19α-dihydroxyurs-12-en-28-oic-acid 28-β-d-glucopyranosyl ester (II), 3β-[(α-l-arabinopyranosyl)