It was shown that the following two solvent systems: (1) acetone-hydrochlorio acid-potassium thiocyanate (10%)(8:1:2.5) and (2) acetone-hydrochloric acid-citrio acid (10%) (8:1:1)，were satisfactory for the separation of niobium and tantalum by the circular paper chromatography on Hsin-Hua No.1 filter paper.Tantalum remained almost at the original spot, and niobium was near the front.Increasing the concentraLion of hydrochloric acid from 1 to 12N in both solvent systems did not affect the R_f value of tantalum but increased that of niobium greatly.The optimum acidity for the separation was found to be 4 to 8N.