The determination of ruin in Cydonia oblonga, Ecballium elaterium, Fraxinus angustifolia, Jasminum fruticans, Marsdenia erecta, Mimosa pudica, Nicotiana tabacum, Paliurus spina-christi and Ruta montana was carried out by using a sensitive reversed-phase high performance liquid chromatographic method Chromatographic analysis war achieved on I LiChrospher 100 RP18 5 mu m column by using an isocratic mixture of water, methanol and glacial acetic acid (65:30:5) at a flow rate of 0.8 ml/min as a mobile phase. The UV detection was performed at 259 nm.