Abstract: Objective To investigate the short-term clinical efficacy and related influencing factors of lacrimal passage exploration combined with indwelling probe application of gatifloxacin gel in the treatment of infants older than 6 months with complicated nasolacrimal duct obstruction. Methods Retrospective analysis of the clinical information of 123 cases (123 eyes) from June 2014 to February 2017 of infants (age>6 months) with complicated nasolacrimal duct obstruction, follow-up children's short-term efficacy and complications of treatment. Results After a short-term follow-up, 115 eyes of 123 eyes reached the cure standard, and the overall cure rate was 93.4%. There were no serious intraoperative and postoperative complications except for 12 cases of orbital edema. Among different age groups [6-12 months group (96.8%) vs. 12-24 month group (91.1%) vs. >24 month group (86.7%)], among different blockage groups [upper segment group, (92.1%) vs middle segment Group (85.7%) vs. lower group (97.5%) vs. 2 or more sites (95.8%)], and between different obstructive groups [bone group (95.8%) vs. membranous group (85.7%)], there was no significant difference in cure rate respective (P>0.05). Conclusion Lacrimal passage combined with indwelling probe application of gatifloxacin gel is a simple, safe and effective new method for the treatment of complicated nasolacrimal duct obstruction in infants. It is suitable for a variety of clinical classification.