In order to investigate the low liquor ratio dyeing method of poly(ethylene tereqphthalte)(PET) fiber, a basic study on two phase dyeing method was studied. The results are as follows; 1. Toluene, xylene, perchloroethylene, tetrachloroethane, and monochlorobenzene are effective as solvent, being considered their boiling points, solubilities in water, and the solubility of dye. 2. Dye partition quantity from solvents to water was proportional to the dissolved quantity of dye in solvents. 3. The crystallinity change of PET fiber dyed by two phase dyeing method had little difference from that of fiber dyed in water. 4. Initial dyeing rate of two phase dyeing method was greater than that of dyeing in water, and the solubility of dye in solvents had much influence on initial dyeing rate, but bath ratio had little. 5. Polymer coagulant was effective to the purification of dyeing waste-water. It was much easier because there was no auxiliaries in the two phase dyeing bath.