This method has been validated with the following criteria: Specificity, with an accuracy of the recovery rate in the range of 97 - 103%, a repeatability with RSD < 2%, with the limit of quantification and limit of detection for amoxicillin are at 2, 0144 mg / l and 0, 61 mg / l; and for clavulanate potassium they are 0, 6 mg / l and 0, 18 mg/l,. By using this method, amoxicillin and clavulanic acid were simultaneously quantified in Augmentin tablets that meet the standards of Vietnamese Pharmacopoeia.