Lacrymation is a common clinical symptom of ophthalmology. In recent years, there been an increasing number of outpatients with symptoms of lacrymation for eye clinics. Both lacrymation and epiphora present tears in clinical manifestation. Epiphora refers to tears at a special pathologic state. However, many ophthalmologists are not clear about the difference between normal lacrymation and epiphora as various reasons can cause tears. This paper mainly reviewed the etiology, mechanism, treatment and prognosis of epiphora as well as the existing problems to be solved.