Abstract : From the point of view that soldering of titanium with gold solder is necessary for its application to partial dentures, the put pose of this study was to estaljlish a technique of dental soldering with 16 karat gold solder. Success or failure of titanium soldering depends on the leveI of oxidation control. Therefore, a technique for vacuum furnace soldering was introduced. The influences of the vacuum degree and holding time on the soldering strength were investigated separately, and the best condition for each was considered. The technique was compared with the conventional techniques of infrared soldering in an atmosphere of argon gas, and the possibility of applying it in the dental clinic was considered. The results were as follows : I . The lowest vacuum degree for successful soldering was 7.5 x 10-3 torr and a soldering strength of about 37 kgf/mm2 was obtained. 2.Holding is unnecessary, because the soldering strength tends to decrease with increase of holding time. 3. Good soldering strength could not be obtained by the present infrared soldering technique because of insufficient oxidation control.