Abstract: The safety and efficacy of the therapeutic radiopharmaceuticals directly depends on its dosage. In order to determine the radioactivity of 153Sm—EDTMP Injection accurately with dose calibrators, and ensure the safety and efficacy of the 1153Sm—EDTMP Injection, the standardization for the radioactivity measurement of 153Sm—EDTMP Injection with dose calibrators has been studied, in which 4π liquid scintillator and 4πβ-γ coincidence method are used to determine the values of radioactivity for the 153Sm—EDTMP Injection standard source with 6 experimental set-ups in four laboratories, then the dose calibrators are calibrated with the standard source, and the effect of the type of dose calibrator, the container of the standard source, and the volume of the solution are studied systematically, at last determine the measurement conditions.