OBJECTIVE： To a evaluation method for the measurement uncertainty for the content of Bisacodyl enteric-coated tablet. METHODS： HPLC external standard method was conducted for content determination of Bisacodyl enteric-coated tablet， and mathematical model for uncertainty evaluation was established to systematically analyze and evaluate the influential factors in processes of solution preparation and instrument measurement. RESULTS： HPLC external standard method showed the content was 97.8％， confidence probability was 95％， expanded uncertainty was 2.8％， and determination result was （97.8±2.8）％，k＝2. CONCLUSIONS： The established method is suitable for the evaluation of measurement uncertainty for the content of Bisacodyl enteric-coated tablet. Regularly calibrated verification for HPLC equipment and strict control of the weighing process will help to improve the accuracy measured by HPLC.