The purpose of this study was to evaluate the clinical efficacy of a standardized special ethanol extract from Gynostemma pentaphyllum as a management for anxiety and stress of normal population. This is a two-arm, parallelgroup, randomized, double blind clinical trial comparing Gynostemma pentaphyllum extract 200 mg bid (GP-EX, n=48) or placebo bid (n=54). The main outcome measures were the decrease in anxiety sensitivity index (ASI), the State version (S-STAI) of the Stait-Trait Anxiety Inventory (STAI) and the Trait version (T-STAT) of the STAI from baseline over a 6 weeks treatment period. In more anxious group (S-STAI50 or ASI19), the anxiety in group with GP-EX was decreased significantly than one in normal population with placebo [S-STAI50: T-STAI = from $57.7{pm}6.5$ ($mean{pm}S.D.$) to $46.8{pm}11.2$ in normal population with GP-EX, p=0.002 vs. from $54.1{pm}9.9$ to $49.0{pm}9.6$ in normal population with placebo, p>0.05; ASI19: T-STAI = from $47.2{pm}12.0$ to $42.4{pm}11.1$ in normal population with GP-EX, p=0.022 vs. from $48.7{pm}11.5$ to $46.0{pm}10.4$ in normal population with placebo, p>0.05]. The most frequently reported adverse reactions considered possibly related to treatment were mild gastrointestinal events. GP-EX is more effective than placebo and is well tolerated as a therapy for anxiety and stress of normal population.