A reversed phase high-performance liquid chromatography method was established for the first time to simultaneously qualify the seven major diterpenoids in Pseudolarix kaempferi, namely pseudolaric acid B O-beta-D-glucopyranoside (1), pseudolaric acid C2 (2), pseudolaric acid C1 (3), deacetylpseudolaric acid A (4), pseudolaric acid A O-beta-D-glucopyranoside (5), pseudolaric acid B (6) and pseudolaric acid A (7). The optimal conditions of separation and detection were achieved on an Inertsil ODS-3 column with gradient elution of methanol and 0.5% aqueous acetic acid (v/v) at the flow rate of 0.6 ml min(-1) within 40 min and detection wavelength set at 262 nm. All calibration curves showed good linear regression (r2>0.9999) within test ranges. This method provided good accuracy with recoveries in the range of 94.3-106.1% and good precision with R.S.D.s of repeatability and intermediate precision less than 0.57% and 4.67%, respectively. The method was successfully applied to qualitative and quantitative determination of 20 P. kaempferi among the 54 samples collected from different areas. The results revealed that the commercial crude drugs were seriously confused and the developed HPLC assay could be used as a suitable qualitative and quantitative determination method for P. kaempferi.