Abstract: The sample of essence was extracted with ethanol,and the solution obtained was determined rapidly by UPLC. The ACQUITYTM BEH C18 column was used as stationary phase;and a mixture of acetonitrile and acetic acid was used as mobile phase;positive electrospray ionization as well as multiple reaction monitoring mode was used in the detection. Ion pair used for qualitative analysis was: m/z 147.2,65.0,ion pair use for quantitative analysis was m/z 147.2,91.0. Linearity range was found between 20-8 000 μg·L-1,and the detection limit (3S/N) found was 10 μg·L-1. Values of recovery found by addition of standard coumarin were found in the range of 96.6%-101.0%,and values of RSD (n=5) was in the range of 3.9%-5.7%.