Several social, psychological and biological factors could be cause for central nervous system disorders, especially anxiety; the latter could lead to more serious neurological and psychosomatical disorders. Sedative medications of plant origin are widely used practically as an alternative and/or additive to traditional pharmacological treatments of anxiety, hyperexcitation and other neuroses. Thus, the search of new effective sedatives based on plant extracts is an actual and perspective task.
 Aim of the present work is to investigate the sedative effect of biomass extract from cell culture of Rauwolfia serpentina K-27 strain.
 Sedative action of biomass extract from cell culture of Rauwolfia serpentina high-productive strain was determined by open field method on 24 white mice males (no line). Mice weight was in 18–25 g interval. The behavior was assessed by usual behavioristic acts: motor activity, psychoemotional activity and tentative research reaction. Animals were randomized into 3 groups of 8 individuals each. Rauwolfia serpentina biomass extract at doses of 7.5 mg/kg (group 1) or 15 mg/kg (group 2) was administered orally as an aqueous solution. Animals of the control group (group 3) received a solvent (distilled water).
 The sedative effect of extract was discovered in doses of 7.5 and 15 mg/kg, that showed a decrease in horizontal motor activity to 63.31 and 79.76% respectively, vertical activity to 82.05 and 71.79%, grooming duration to 57.28 and 60.78% at experimental days 20 to 28. Tentative research reaction demonstrated the direct dependence of sedation intensity on duration of extract administration. As a result of the conducted researches significant differences in the number of fecal bolus of both experimental and control groups of mice were not revealed. No significant difference between the sedative effect and the dose (7.5 and 15 mg/kg) was observed.
 The sedative effect of biomass extract from cell culture of Rauwolfia serpentina K-27 strain was proven. This leads to perspective inclusion of the extract to traditional medicine in prophylaxis and treatment of insomnia and of physical and psychological overexcitation.