PURPOSE:To enable isolation of an organic compound of high purity in high efficiency, by clathrating the organic compound with a cholic acid or its derivative without complicated and expensive operations, e.g., rectification or column chromatography. CONSTITUTION:An organic compound selected from formulas: R -Y, R -O-R , R -COOH, R -COOR , R -CO-R , R R R N, R -Z or compendious of formulas I and II [R -R are alkyls (R and R -R have 1-5 carbon atoms and R may be substituted with halogens; R and R bear 1 carbon atom or 3 to 8 carbon atoms; R has 2-8 carbon atoms), cycloalkyl, aryl (R and R -R have 6-8 carbon atoms), further R -R , R , R are H; Y is OH, CN, NO2; Z is halogen; R , R are ethylene; X is O, C-C bond; R is 2-8C alkylene] is clathrated with cholic acid or its derivative and made hard soluble in an organic solvent such as acetone. Thus, the organic compound is easily and effectively purified.