We propose a recycling system that can recover the useful water from the spent water soluble coolant by using a surfactant and powdered activated carbon. The processing of about 70 liters of actual spent water soluble coolant yielded about 60 liters of clear water with 6.7 of pH and 0.0 of Brix value. About 120 liters of recycle water-soluble coolant was prepared by diluting an emulsion type cutting fluid 20 times with the recycle water. The recycle coolant has been showing the very similar Brix value and pH changes as those of virgin coolant until 100 days usage. The recycle coolant also showed the same potential to inhibit the progress of flank wear as that of virgin coolant. These facts indicate that the recycled water can be utilized as a dilutor of renewal water-soluble coolant.