Objective: To summarize the clinical characteristics of congenital lacrimal fistula for reference in its clinical diagnosis and treatment. Methods: Retrospective case series study. The clinical data of 27 patients (32 eyes) with congenital lacrimal fistula admitted to the Lacrimal Center of Third Medical Center of PLA General Hospital from July 2011 to November 2017 were analyzed, including gender, age of diagnosis, left eye or right eye, family history, physical examination, ophthalmic examination, fistula opening location and appearance, symptoms, results of lacrimal duct irrigation, three-dimensional reconstruction of the lacrimal drainage system with CT, lacrimal endoscopy, treatment, outcomes and follow-up. Results: In the 27 patients, the male to female ratio was 1∶2. The age of diagnosis was 1 to 74 years old, and the median was 32 years old. The ratio of unilateral fistula to bilateral fistula was 4.4∶1 (22/5), and the ratio of left eyes to right eyes was 1.2∶1 (12/10). The disease was sporadic in 22 patients, and 5 patients had a family history. Genetic analysis showed that congenital lacrimal fistula presented autosomal dominant inheritance. Fistulas were found on the skin surface of the lacrimal sac area under the medial canthus in 30 eyes, on the lacrimal caruncle in one eye, and on the conjunctiva of the medial canthus in one eye. All the patients presented with epihora, and irrigation liquid outflowed from the fistulas with purulence in 18 eyes. Lacrimal CT of the 27 patients showed contrast agents were left in the lacrimal sac. Lacrimal duct fistula was found open in the common canaliculus with concretions in the lacrimal system in four patients. Eight patients with mild symptoms underwent observation. Three patients underwent lacrimal therapeutic irrigation and probing. Sixteen patients underwent fistulectomy and were cured without recurrence during the follow-up of 1 to 6 years. Conclusions: Congenital lacrimal fistula is usually unilateral, and the opening is mostly located on the skin surface of the lacrimal sac area under the inner canthus ligament. Most cases are sporadic, and some cases are of familial inheritance in an autosomal dominant condition. (Chin J Ophthalmol, 2020, 56: 688-692).