Placental site trophoblastic tumor (PSTT) refers to intermediates derived from intermediate trophoblasts, a particular type of trophoblastic tumor from the placenta site (gestational trophoblastic disease, GTD), whose pathological morphology and biological behaviors and other trophoblastic tumors are very different. Here, the authors report one case of PSTT, which is from the Anhui Provincial Hospital Affiliated to Anhui Medical University. A 39-year-old woman presented with abnormal uterine bleeding for four months after she had an abortion. She underwent curettage surgery in a local hospital, revealing a pathology of choriocarcinoma. Methotrexate (MTX) chemotherapy was ineffective, and blood hCG continued to rise, while in this hospital ultrasonographic examination the bottom of the uterus exhibited a uneven echo, with ill-defined and unclear intrauterine boundaries and a “honeycomb” structure in the serosa. After hysterectomy ,pathology revealed a bottom PSTT with invasion of the muscle which was greater than 50%. Microscopically, the tumor consists of sheets of intermediate trophoblastic cells invading the myometrium. Immunohistochemistry showed positive results for PCK, inhibin, hPL, and β-HCG (spotty +). A course of combined EMA-CO chemotherapy was performed ten days after the surgery, and the patient was then discharged after reviewing the normal indicators. The patient was followed for 36 months without recurrence.