A method of reversed-phase high-performance liquid chromatography (RP-HPLC) was established for the simultaneous determination of gallic acid, protocatechuic acid, catechin, vanillic acid, caffeic acid, ferulic acid, rutin, quercetin and syriacusin A in the ethanolic extracts from the five parts (roots, stems, leaves, seeds and exocarps) of Abutilon theophrasti Medic. The nine components in the sample were extracted with 70% ethanol solution in an ultrasonic bath for 25 min and chromatographically separated on a C18 analytical column (250 × 4.6 mm i.d., 5 µm) by gradient elution with water containing 0.1% (v/v) formic acid (pH 2.4) and acetonitrile as mobile phases, at a flow rate of 1.0 mL/min. The detection was conducted by ultraviolet-visible absorption. The proposed method showed good linearity between the peak area of each analyte and its concentration. Relative standard deviations of the instrumental intra-day and inter-day precision and method precision were less than 2.0, 3.5 and 2.0%. Recoveries were within the range of 87.3-100.8%. Limits of detection and quantification were 0.045-0.400 µg/mL (signal-to-noise ratio: 3) and 0.090-1.115 µg/mL (signal-to-noise ratio: 10), respectively. The proposed method was successfully applied to determine common phenols and flavonoids of Abutilon theophrasti Medic. The results indicated that the RP-HPLC system may provide a rapid method for the quality control of Abutilon theophrasti Medic.