the solution which comprises an organic compound containing at least a polymer before or when the solution is supplied into the distillation tower and the organic compound is replaced with water this replacement can decrease the amount of water to be entrained in the organic compound which will be recovered and also the amount of the organic compound mixed in the aqueous solution containing the solid which will be removed from the bottom it is preferable to concentrate the solution to some extent for example from one tenth to one twentieth of the initial volume with an evaporator prior to the treatment in the distillation tower so as to decrease the amount of added water the method of the present invention will be explained in detail by referring to the accompanying drawing a solution comprising an organic compound containing a polymer such as pva pvac etc and an alkali metal salt such as ch 3 coona is generated in the process for preparing pva such the solution may be optionally concentrated with a conventional separating means such as a distillation tower an evaporator and the like in fig1 the solution is supplied into an evaporator 2 through a supply line 1 when the evaporator is used waste heat from other steps may be used as a heat source but a multiple effect evaporator in which a steam from one evaporating unit is used for heating the subsequent one is thermally advantageous the preconcentrated solution is supplied into a distillation tower 7 through a line 4 for supplying a bottom liquid from the evaporator 2 at the same time water is supplied into the tower 7 through a water supply line 5.