A novel therapeutic agent for ectopic pregnancy having a therapeutic effect for ectopic pregnancy, especially unruptured ectopic pregnancy, and a novel method of screening a therapeutic agent for ectopic pregnancy are disclosed. The therapeutic agent for ectopic pregnancy contains as an effective ingredient a suppressor of brain-derived neurotrophic factor (BDNF) and/or of brain-derived neurotrophic factor receptor (TrkB). The method of screening a therapeutic agent for ectopic pregnancy includes measuring the kinase activity of TrkB in the presence of a test substance and the kinase activity of TrkB in the absence of the test substance; and selecting the test substance which decreases the kinase activity of TrkB.