Results of property study of the developed high-acting scintillation spectrometer to be used in x-ray densitometer of radioactive solutions with 241Am "transmitting" radiant are presented. Fast crystals YAlO 3:Ce (Æ25x0.4 and Æ25x1.0 mm) are used as scintillators. S trong energy resolution dependence of the spectrometer with thin scintillators at crystal illumination (from 16.3 to 20.3 % for a g-line 59.5 keV) is revealed. The spectrometer input count-rate is over 5·10 5 1/s, and spectrum accumulation speed is not lower than 2·10 5 1/s. Due to the conversion gain program stabilization the relative shift and the peak broadening E γ = 59.5 keV do not exceed 0.25 % and 7.5 %, accordingly.