OBJECTIVE: To establish a method for the determination of related substances in regorafenib. METHODS: Gradient elution HPLC was performed on the column of Waters Atlantis T3 C18 with mobile phase A of 0.1% Trifluoroacetic acid solution and B of acetonitrile (gradient elution) at a flow rate of 1.0 ml/min, the detection wavelength was 232 nm and column temperature was 35 ℃, injection volume was 10 μl. RESULTS: AFP-PMA urease (impurity A), FP- dimethyl pyridine carboxamide (impurity B),3,4-bis-CTF-aminoformamido-PMA (impurity C), regorafenib and other impurities were well separated; the linear range was 0.511-5.108 μg/ml for impurity A(r=0.999 9), 0.287-2.869 μg/ml for impurity B(r=0.999 5), 0.360-3.604 μg/ml for impurity C(r=0.999 9) and 1.444-14.442 μg/ml for regorafenib (r=0.999 8); the detection limit were 0.052,0.022,0.084 and 0.071 μg/ml,respectively; RSDs of precision, stability and reproducibility tests were lower than 3%; recoveries of impurity A, B and C were 102.7%-106.3% (RSD=1.09%,n=9), 98.2%-102.9% (RSD=1.83%,n=9) and 98.6%-104.3% (RSD=1.57%,n=9). CONCLUSIONS: The method is sensitive, rapid, accurate and reliable, and can be used for the determination of related substances in regorafenib.