OBJECTIVE：To establish the method for content determination of related substances in Paracetamol tablets. METHODS：HPLC method was adopted. The determination was performed on Agilent 5HC-C8 column with mobile phase A consisted of methanol-water-glacial acetic acid （50 ∶ 950 ∶ 1，V/V/V）and mobile phase B consisted of methanol-water-glacial acetic acid（500 ∶ 500 ∶ 1，V/V/V）（gradient elution ）at the flow rate of 0.9 mL/min. The detection wavelength was set at 254 nm，and column temperature was 40 ℃. The sample size was 5 μL. RESULTS：Under the chromatographic condition ，the resolutions of main component （paracetamol），6 known impurities （p-aminophenol，p-chloroacetanilide，impurity A ，B，D，F），3 specific excipients（methyl hydroxybenzoate ，ethyl hydroxybenzoate ，propyl hydroxybenzoate ）and 1 unknown impurity were all higher than 1.5. The linear range of 6 known impurities were 0.539-1.617，0.026-0.384，0.237-17.799，0.257-19.271，0.239-17.955， 0.246-18.462 μg/mL（r≥0.999 8），respectively. Correction factors of impurity A ，B，D，F were 2.9，1.0，1.2，6.2. The limits of detection were 0.009 6，0.024 2，0.164 0，0.051 1，0.055 9，0.422 0 ng；the limits of quantitation were 0.032 0，0.080 6，0.546 0，0.170 0，0.186 0，1.406 0 ng. Average recoveries were 95.96％-111.09％（RSDs were 0.05％-2.42％）. The RSDs precision test were low than 15％，and the durability were good. p-aminophenol（all were 0.006％），impurity B （0.016％-0.017％）and unknown impurity（0.002 0％-0.002 1％）were detected in 3 batches of sample. p-choroacetanilide，impurity A ，D and F were not detected. CONCLUSIONS：The method is specific ，accurate and suitable for the determination of related substance in Paracetamol tablets.