The occurrence of lacrimal passage obstruction diseases is closely related to the physiological parameters of lacrimal passage. The lacrimal passage is divided into membranous lacrimal passage and bony lacrimal passage. Computed tomography (CT) of lacrimal passage can help us understand the situation of bony lacrimal passage and clarify the impact of individual anatomical differences on the occurrence of diseases. The following chapters present the physiological parameters of lacrimal passage measured by lacrimal passage CT and the impact of anatomical structure of lacrimal sac fossa on endoscopic dacryocystisinostomy, and analyze the relevant anatomical parameters of the dacryocystitis patients, including the angle between the nasolacrimal passage and the nasal plane, and the correlation between the deviation of the nasal septum and the occurrence of dacryocystitis.