Neonatal lacrimal dacryocystitis is caused by secondary infection due to obstruction of the lower end of the nasolacrimal duct by the embryonic remnant membrane that has not degenerated, and retention of tears and bacteria in the lacrimal sac. About 2-4% of full-term infants may have such obstruction, but the majority of them are expected to atrophy on their own within 4-6 weeks after birth and regain patency. Bony nasolacrimal ducts due to dysplasia and stenosis are less common. Tearing after birth and frequent discharge should be highly suspected of neonatal dacryocystitis. The diagnosis of neonatal lacrimal dacryocystitis can be confirmed by pressing on the lacrimal sac area and having the discharge spill out from the tear dots. Massage the lacrimal sac mass downward with the finger, and if the cyst suddenly disappears, it means that the residual membrane has been squeezed, which means that it is cured. If after 4-6 months of conservative treatment, including multiple massages still do not work, the lacrimal sac can be probed with a probe, and more can be cured. If probing does not work, consider whether there is a bony narrowing of the lacrimal duct and perform lacrimal balloon dilation or tear duct placement.