A liquid scintillation counting technique was applied to measure the isotope103mRh /half life = 56.12 min/ which is difficult to detect because its -ray is of low energy and low emission probability. Tris-/2,4-pentanedionato/ rhodium /III/ /Rh/ acac/3/ was irradiated with bremsstrahlung of accelerated 3.2 MeV electrons by LINAC. The method has given a reliable calibration curve for the determination of103mRh radioactivity below Rh/acac/3 concentrations of 2 mM. The integrated cross section of103Rh/,
/103mRh determined by this method was found to be 6.8±3.4 b MeV at 3.2 MeV.