Abstract: A GC-MS-SIM method was developed for the simultaneous determination of the 7 coumarins in common cnidium fruit. The 7 bioactive constituents were separated on DB-1 capillary column (30 m×0.25 mm, 0.25 μm) using temperature programming. The interface temperature was set at 280℃; Ion source temperature:250℃; Quadrupole temperature:150℃; EI mode:70 eV; The mass spectrometer detector was in SIM mode; Scan range:50-350 amu. All the 7 marker substances showed good linearity (r²>0.9986) in the test ranges. The LODs and LOQs for the compounds ranged from 1.06 to 10.11 ng ·mL^-1 and from 3.21 to 29.88 ng·mL^-1, respectively. The overall intra-day (n=6) and inter-day (n=3) RSDs were 0.7%-2.5% and 1.2%-3.3%, respectively. The overall recoveries were between 92.38% and 100.50% for all compounds. This method was simple, rapid, sensitive, with good specificity, and it can provide a reference for the quality control of common cnidium fruit.