To understand the characteristics of the sexual behavior and the current status of the contraception of the adolescent, to analyze the reasons of the unwanted pregnancy of the adolescents, and to provide the suggestions for the optimization of the contraceptive methods of the adolescents. Methods: A total of 240 adolescents aged 14-19 years old who underwent induced abortion in Ningxia hui autonomous region people's hospital from January 2018 to December 2022 were collected, and the clinical data of these adolescents were analyzed retrospectively. Results: The proportion of the adolescents with abortion was approximately 3.9% from 2018 to 2022. Among 240 adolescents with abortion, there were 101(42.1%) cases without any contraceptive measures and 139 (57.9%) cases with contraceptive measures. Among the adolescents with contraceptive methods, 74(53.2%) cases had mainly male condoms used, then followed by 23 (16.6%) cases with emergency contraception, 22 (15.8%) cases with the safe period contraception and 20 (14.4%) cases with extracorporeal ejaculation. The main reasons for no contraceptive measures used of the adolescents with abortion were the inconvenient accessing contraceptive devices (47.5%), then followed by the previous uncomfortable sexual experiences (38.6%) and the sense of luck for pregnancy (33.7%). After providing counseling and education services to the adolescents with unwanted pregnancy before and after abortion, the proportion of the excellent grades scores of the contraceptive knowledge questionnaire of the adolescents had increased significantly, and the awareness rate of the contraceptive knowledge of the adolescents after counseling and education services had increased significantly (P<0.001). Conclusion: The rate of the contraceptive used among the adolescents is low, and the main reasons of the adolescents with unintended pregnancy are lack of the scientific knowledge of contraception, and the insufficient sex education for the adolescents. The education departments, the schools, the hospitals and the communities were appeal to strengthen the publicity and education of the contraception knowledge for the adolescents and to enhance the accessibility of the contraceptives and the post abortion services ability of the providers, in order to reduce the adolescent pregnancy rate and to protect the adolescent reproductive health.