Solution plasma can synthesize many kinds of nano-sized metal powder, such as Au and Ag. But calcium compound of nano-sized powder synthesized by solution plasma has not been confirmed. In this study, we tried to synthesize the hydroxyapatite with solution plasma and compared with specific surface area of HAp synthesized by ultrasound irradiation. The specific surface area of HAp with ultrasound was maximum 330 m^2・g^<-1>. On the other hand, the specific surface area of HAp with solution plasma had lower 14 m^2・g^<-1> than that of HAp with ultrasound. We examined optimum conditions, such as initial temperature, suspension concentration and pulse width. The crystal shape of HAp with solution plasma was thin plate-like and the particle size was 70nm.