Abstract: A method for the determination of Al, As, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu.Fe, Mg, Mn, Mo, Ni, P, Pb, Ru, Sb, Sn, Sr, Ti, V, W and Zn 25 trace elementsin U_3O_8 is reported. The sample is dissolved in HNO_3 or HNO_3--HClO_4--HF and theuranium is separated by TBP levextrel resin chromatography. The impurity elements.containing in the aquaous phase are determined by horizontal ICP/AES method.With a sample of 300 mg, the detection limit for all the 25 elements is in theranag of 0.01×10~(-6)～5×10~(-6), the recovery is in the range of 82%～121%, therelative standard deviation (RSD) is less than 13%. 18 trace elements in reference material of U_3O_8 prepared in China are deter-mined, the values obtained agreed well with the values of overall median of acce-pted laboratory means.