To establish a method for determination of quercetin content in fructus trichosanthis, and to observe the inhibitory effect of fructus trichosanthis extract on growth of cervical carcinoma HeLa cells. Active constituent was determined by HPLC with quercetin as the reference using 0.3% phosphoric acid: methanol solution (47:53) as the mobile phase at a detection wavelength of 360 nm. MTT assay was used to determine the cell metabolic rate, while flow cytometry was utilized to observe the changes in apoptosis. Quercetin showed good linearity within a 1.0468-10.468 mg/mL range (r=0.9997), with an average recovery of 98.58%. Compared to the control group, different concentrations of fructus trichosanthis extracts all inhibited HeLa cell proliferation after acting on for 24 and 48 h. Moreover, inhibition rates increased significantly with increasing drug concentrations and prolonging treatment time, showing a certain time-dose-response relationship. S phase ratio of HeLa cells rose from 24.68% in the control group to 42.15%, while G2 phase cell ratio dropped from 10.54% in the control group to 5.11%. Fructus trichosanthis extract could arrest HeLa cells in S phase. Compared to the control group, percentage of S phase cells increased, while G2 phase cells decreased. And such effect was dosedependent. The present quantitative determination method is reproducible, accurate and reliable. Fructus trichosanthis extract has a significant inhibitory effect on the growth of HeLa cells in vitro.