OBJECTIVE： To establish the method for the identification of impurities in succinylcholine chloride raw material. METHODS： Two-dimensional UPLC-QTOF-MS was adopted. One dimension chromatographic condition was Hypersil GOLD C18 column using buffer solution （22 mmol/L sodium pentanesulfonate+50 mmol/L sodium chloride+5 mmol/L sulphuric acid） as mobile phase A and acetonitrile as mobile phase B， volume ratio of mobile phase A to mobile phase B 95 ∶ 5， column temperature of 40 ℃， flow rate of 1.0 mL/min， detection wavelength of 214 nm. Two-dimension chromatographic condition was ACQUITY UPLC BEH C18 column using 0.1％ ammonia as mobile phase A and acetonitrile as mobile phase B （gradient elution） with column temperature of 30 ℃ at flow rate of 0.4 mL/min. Ionization mode was ESI+ with capillary voltage of 2.5 kV， source temperature of 120 ℃， temperature of atomizing gas at 450 ℃， flow rate of atomizing gas at 900 L/h， acquisition mode of MSE. RESULTS： The succinic acid， succinyl chloride （intermediate）， pyridine （reagent） and other impurities were detected in succinylcholine chloride by one dimensional method of HPLC. Other 4 obvious unknown impurities were named impurity 1， impurity 2， impurity 3 and impurity 4， among which the apparent content of impurity 2 was the highest. Two-dimensional method of HPLC-QTOF-MS deduced that the impurity 2 was dehydrogenate succinylcholine chloride and impurity 4 was succinylcholine chloride. The impurity 1 and impurity 3 were not detected in mass spectrum. CONCLUSIONS： Establish method for the identification of impurity in succinylcholine chloride raw material， and the results of research are used for the evaluation of the quality of the succinylcholine chloride raw material.