The stability of liquid dyes with various salt contents was tested and new separation process was developed for the preparation of storage-stable liquid dyes. The extent of aggregation of dye molecules in solution was measured with respect to storage time of liquid dyes in different salt environments (NaCI : 1.32-2.67M, Na₂SO₄ : 0.49-0.74M). After one month's storage, the concentration of suspended sol ids were found to be in the range of 10.96g/l to 45.51g/l according to the salt contents. Dye solutions at higher salt concentration exhibited the more suspended solids contents which indicate instability of liquid dyes. Counter Diffusion technology was introduced to prevent the aggregation of dye molecules due to high salt contents. Hollow-fiber membranes were modified by immobilization of a crystalline lattice onto the surface of the membrane. The removal of salt was 10 to 20 % with one pass operation. The separation factors based on removal of salt and dye molecules was high(20 to 700) but the loss of dye molecules was less than 0.4%. The effects of various operating parameters on desalting were investigated, such as flowrate of liquid dye solution and stripping water, the compositions of liquid dye and the life time of immobilized membranes, etc.