Abstract: The technology of long distance oil-gas-water mixted transportation, which has been successfully applied in onshore oilfield development, is applicable as well in the oilfields in desert and beach. The focus of the research includes the law of flow pattern, pressure loss and liquid holdup of the three-phase oil-gas-water flow in horizontal pipes, which is very important to multiphase pipeline transportation. The paper out-lights the above research activities by foreign countries, which are carried out by means of the achievements made in the studies on two-phase flow. Some suggestions are given for the further study on the three-phase gas-oil-water flow in horizontal pipes.