The combination of CTM and GG is often used as an active substances to relieve symptoms of cough and cold. The concentration of CTM and GG in syrup are very low, so that it need validated determination method to ensure therapeutic dose. The purposes of this study were to validate determination method of CTM and GG and to apply the method to some syrups. Determination of CTM and GG in syrup using HPLC JascoLc-Net II/ADC equipped with a UV-Visible detector at a wavelength of 270 nm. The stationary phase used was C18Li Chosphera nd the mobile phase usedwas a mixture of acetonitrile:methanol:water (15:10:75 v/v) with a flow rate of 1 mL/minutes.Validation test was conducted on precision test, accuracy, selectivity, linearity and sensitivity. The method of analysis was applied to syrups fromthree different factories. The result of this research showed that validation tests of CTM and GG met the requirements, were: % RSD of precision test for CTM was 0.18% and for GG was 0.17%; accuracy test resulted good recovery for CTM and for GG in syrups. Good selectivity; linearity with a correlation coefficient 0.999; LOD for CTM and GG were 2.40 and 3.07 µg/mL; LOQ for CTM and GG were 8.00µg/mL and 10.24 µg/mL. The level of CTM and GG in syrups were compliance with the requirements by the Indonesian Pharmacopeia Edition V.