Abstract: α spectrometry is a direct method to measure α-emitting radionuclides, which has the advantages of low detection limit and short time-consuming. The electrodeposition method is the most ideal technique for preparation of source for α spectrometry, by which the source is homogeneous and self-absorbance negligible. To obtain high quality of electrodeposition sample of ²²⁶Ra, the effects of the quality of chloroplatinic acid, current density, electrodeposition time, initial pH and concentration of ammonia oxalate on electrodeposition yield of ²²⁶Ra were investigated on the base of the ammonia oxalate/hydrochloric acid electrolytes. The results show that under the conditions of chloroplatinic acid doseage of 700 μg, the current density of 0.225 A/cm², the electrodeposition time of 60 min, the concentration of ammonia oxalate of 0.05-0.13 mol/L, the initial pH of ammonia oxalate of 1.0-2.5, the electrodeposition yield of ²²⁶Ra is over 95%.