Objective:To explore the synergistic anti-tumor effect of alcohol extract of verbena officinalis(EVO) and paclitaxel (PTX). Methods:S180 cells were cultured in vitro, and the growth inhibition effects of the two drugs used respectively and in combination were detected by MTT methods. S180 transplant model was established in male ICR mice, and the tumor growth inhibition effects of the two drugs were calculated by measuring tumor volume in every two days. Results:In vitro experiment showed that cell growth was significantly inhibited by PTX when EVO was added concomitantly at a dose of 20 mg/ml. Moreover,in vivo experiment demonstrated that EVO(1 g/kg) efficiently enhanced the anti-tumor effect of PTX at a dose of 10 mg/kg. Conclusion:A subclinical dose of EVO could greatly improve the anti-cancer effect of paclitaxel,which provide a new strategy to amplify the efficiency of chemotherapeutics without increasing its dose.