The aim of this study was to validate the partial agonistic property of two natural isolated β2-adrenocepotor agonists using rat uteri in vitro functional efficacy test. Our results revealed that the combination of the two agonists exhibited intermediate relaxing effect represented as dose-response curve with 50% Emax of terbutaline, which confirmed by the effect of the selective β2-adrenoceptors antagonist ICI118.551, and their significant inhibition of terbutaline relaxing effect in both uteri. Finally, both isolated compounds are considered as partial β2- adrenoceptors agonists.