The miniaturization of column and the selective separation of R. E. are discussed in this paper. The rare earth elements are quantitativly separated from Zr, Ti, U (VI)，Bi(llI)，Ba, Sr, Ca, Mg, Fe, AI, monovalent and some other divalent metals by elution with 1.25 N nitric acid- 4% tartaric acid-0.1% ascorbic acid from a column (0.6-llcm) of cation exchange resin. The retained RE elements can be completely eluted with 3 N hydrochloric acid. The remain- ed thorium can be finally eluted with 10 ml of 2% ammonium oxalate and determined. This method has been used for measuring the contents of fifteen RE elements in minerals and rocks with ICP-AES.