A review with 39 references on the advances in pharmacol. studies on glycyrrhizic acid, glycyrrhetinic acid, diammonium glycyrrhizinate, and carbenoxolone in the protection of encephalic injury and the improvement of memory, and the suggestion that the encephalic protection of glycyrrhizic acid is a comprehensive result of the basic actions with anti-inflammatory, anti-oxidative, anti-apoptosis, anti-cholinesterase, and moderate glucocorticoid-like effects.