There is provided a method for manufacturing a one-piece dental implant having a ceramic abutment and a titanium or titanium alloy implant fixture firmly adhesively fixed to each other. A one-piece dental implant having an abutment 2 and an implant fixture 1 integrated to each other is manufactured by cooling the implant fixture 1 to room temperature after a projecting part 2a of the abutment 2 at room temperature is press-fitted into a recess part 1a of the implant fixture 1 being in a state where the implant fixture 1 is heated to 100-300 °C. The implant fixture 1 formed of titanium or a titanium alloy is perforated to have a truncated circular cone-shaped recess part 1a. The recess part 1a has a taper that is tapered from an intraoral side to a jawbone side. The abutment 2 formed of ceramic has a prosthetic fixing part 2b provided on an opposite side of the jawbone side and a truncated circular cone-shaped projecting part 2a provided on the jawbone side. The projecting part 2a has the same taper as the recess part 1a of the implant fixture 1.