In this study, the effect of season and region on the chemical composition of licorice root, such as ash, sugar content and specially glycyrrhizic acid (G.A.) were examined. Licorice roots were collected from five region, Eghlid, Beiza and Doshman ziari in Fars province, Kerman in south and Kermanshah in west of Iran . After preparation of roots for experiments, extraction process was performed by heat reflux extraction. The extract has been oven dried in 105°C. Then, some chemical experiments were performed on extract powder according to Iran standard number 2343 and 6699. The amount of glycyrrhizic acid was also measured by High Pressure Liquid Chromatography (HPLC). In continue, experimental results were analyzed by SAS software. Results show that the effect of season on sugar content and also the effect of region on all composition are significant at a reliability of one percent. Also, the effect of interaction between season and region on ash and sugar content is significant. According to results, Kerman licorice has maximum and Kermanshah licorice has minimum amount of ash. Also, Kerman and Kermanshah licorice has maximum and Beiza licorice has Minimum content of sugar. Sugar content for licorice roots that harvested in fall is more than of licorice roots that harvested in summer. HPLC results show that, amount of G.A. varied from 4.4 up to 11.7 percent depend on region. Maximum amount of G.A. was found in Beiza licorice and minimum amount was found in Kermanshah licorice. The effect of season on G.A. is also significant for Beiza and Eghlid licorice. Eghlid licorice has maximum amount of G.A. in summer and Beiza licorice has maximum amount of G.A. in fall.
