Abstract: Tubal ectopic pregnancy is the most common ectopic pregnancy，and constitutes almost 98% of that.However，the etiology and accurate mechanisms of tubal ectopic pregnancy are not completely understood still. For a long time，tubal anatomy morphology distruction such as abnormal endotubal morphology，inflammatory adhesions and tubal stenosis or obstruction，which result from risk factors such as fallopian tube surgery or genital tract infection and so on，are deemed to be the main etiology of tubal ectopic pregnancy. The current literature suggests that abnormal embryo-tubal transport including changes of tubal smooth muscle contractility or ciliary beat activity and alterations in the tubal environment may be important potential pathological mechanisms of tubal ectopic pregnancy. Besides，immunity and cytokines may also play a relevant role in the formation of tubal ectopic pregnancy.

Key words: Pregnancy, tubal, Pregnancy, ectopic, Progestins, Estrogens