ABSTRACT
Glycyrrhiza Glabra [Licorice] root, a member of the pea family has been used since ancient times as both food and medicine. Licorice has been used as an antioxidant, antimicrobial and anti inflammatory in researches.Extraction of this medical plant is used as the basis of anti-ulcer medicine for treatment of peptic ulcer. In the present study, licorice decoction [20gr/dl,33gr/dl] was prepared and anti microbial activity on helicobacter pylori growth was studied by disk diffusion method and cup plate method. The results showed that licorice decoction 33gr/dl by disk diffusion method inhibited growth of helicobacter pylori in vitro the same as metronidazole.[P value=0.709] However, it does not have anti bacterial activity against helicobacter pylori like amoxicillin and clarythromycin [Pvalue-0.000]. Decoction licorice [20gr/dl, 33gr/dl] can not be used as an alternative to choice antibiotic [amoxicillin, clarythromycin] in vitro