Abstract : The chemical composition of growing Silybum marianum in the south-eastern part of Uzbekistan: the amount of silymarin and flavonolignans was studied. Silybum marianum has almost no contraindications and is rich in chemical composition, which positively affects the body and human health. It can normalize the work of a number of body systems in a short time and strengthen the immune systematic, and this directly depends on the amount and concentration of biochemical compounds contained in its chemical composition. We analyzed the dry extract of the seed in HPLC and paid special attention to the number of Flavolignans contained in it. It has been studied that the full effect of flavonolignans contained in Silybum depends on its chemical concentration in terms of importance and stable antioxidant performance. This article describes the results obtained when the taxifolin, Silibin, Silidianin and Silikristin flavonolignans after the results in HPLC were continued in mass spectrometry.