AIM:To observe clinical effect of probing of lacrimal passage for treatment of neonatal dacryocystitis with different age.METHODS:Probing of lacrimal passage in surface anesthesia was performed in 532 infants 590 eyes from November 2009 to September 2010 in our department of ophthalmology,including male 321(358 eyes),female 211(232 eyes),aged from 3 months to 48 months.RESULTS:Totally 456 eyes received the operation in group 1(aged from 3 months to 6 months)and 442 eyes were cured(96.9%);95 eyes received the operation in group 2(aged from 2 months to 12 months)and 83 eyes were cured(87.4%);39 eyes were in 3 group(age≥13 months)and success rate of the operation was 82.1%.There was significant difference between group 1 and group 2,group 1 and group 3(P<0.05,χ2=15.986,χ2=19.578 respectively)while there was no significant difference between group 2 and group 3(χ2=0.642,P>0.05).CONCLUSION:Probing of lacrimal passage is an effective treatment for neonatal dacryocystitis and the best time for probing of the lacrimal passage is 3-6 months after birth.