Abstract: OBJECTIVE To establish a bacterial endotoxin test method for fosaprepitant dimeglumine. METHODS The methodological study of fosaprepitant dimeglumine was carried out by gel colt method, dynamic chromogenic method and recombinant factor C method. RESULTS The result of gel colt method was positive in the range of detection concentration, which did not meet the premise of the gel colt method for interference experiments. In the dynamic chromogenic method, when the recovery ratio of different dilution multiples met the requirements of the pharmacopoeia, the endotoxin detection results were extremely different(the difference was greater than 200 times), and the problem still existed with the use of endotoxin-specific buffer. When the sample concentration was lower than 0.062 5 mg·mL^-1, there was no interference existed, and the results were in compliance with the regulations using recombinant factor C method. CONCLUSION It is not possible to detect endotoxin in fosaprepitant dimeglumine by classical gel method and dynamic chromogenic method. The recombinant factor C method can be used for the endotoxin quality control of fosaprepitant dimeglumine based on the methodology research.