The present article describes a new developed method for the simultaneous determination of ( )-catechin (1) and (-)-epicatechin (2), separated via HPLC. The method has been validated and applied on the real samples and 1 has been detected in both aerial and root parts of Alhagi camelorum without any ambiguity of fake positive or negative presence of 1 or 2 by virtue of dual detection system of UV and Mass Spectrometry. The antioxidant capacity was also investigated and a linear correlation has been noticed between the antioxidant capacity and the catechin amount in A. camelorum extracts.