PIP: 315 women who underwent Sino-implant II implantation and 302 healthy women were recruited and followed-up for 3 years in order to observe the effect of Sino-implant II on uterine myoma and ovarian cysts. Blood pressure measurement, body weight measurement, vaginal ultrasonic examination, and cervical smear were performed once a year. The results show that Sino-implant II did not influence blood pressure and body weight. There were more ovarian cysts in the Sino-implant II group than in the control group, but they were all found to have disappeared when reexamined after menstruation. These ovarian cysts may have been follicular cysts. There were fewer uterine myomas in the Sino-implant II group than in the control group, and these myomas developed slowly. The results suggest that Sino-implant II is a safe contraceptive method.