Abstract: The intrinsic kinetics of methanol synthesis in the gas - liquid - solid phase process , starting from carbon monoxide, carbon dioxide and hydrogen over a copper - based catalyst suspended in paraffin as the liquid medium, were studied in a well - mixed, agitated slurry reactor at T = 210-250℃ and p= 3-8 MPa. The results obtained show that methanol can be formed from both carbon monoxide and carbon dioxide hydrogenation reactions. Based on these two reactions a dual -site Langmuir -Hinshelwood mechanism was proposed, and 6 kinetic rate models were derived. After parameter estimation and model discrimination, a final model which gave a good agreement with the experimental results was obtained. The average relative deviations between experimental and calculated conversion rates are 3. 69% and 3. 92% for CO and CO2 respectively.