ObjectiveTo evaluate the occurrence and risk factors of healthcareassociated infection (HAI) in very low birth weight infants (VLBWI, including extremely low birth weight infants).MethodsData of VLBWI (birth weight <1 500 g,length of hospital stay >48 hours)in a neonatal intensive care unit(NICU) from January 2008 to January 2010 were analyzed retrospectively.ResultsOf 77 VLBWI, 18 developed 29 times of HAI, HAI rate was 23.38%, HAI case rate was 37.66%; the main infection site was respiratory tract (55.17%),followed by skin and soft tissue (17.24%) and blood stream (13.79%); a total of 34 pathogenic isolates were isolated, 67.64% (23 isolates)were gramnegative bacilli,the most common pathogens were Klebsiella pneumoniae and Escherichia coli; 14.71%(5 isolates) were grampositive bacteria;17.65% (6 isolates) were fungi, the main fungus was Candida albicans. Univariate analysis indicated that gestational age,birth weight, mechanical ventilation, premature rupture of fetal membrane, and parenteral nutrition were risk factors for HAI（P＜0.05）; multivariate logistic regression analysis showed that birth weight <1 kg(OR 95% CI:1.65-90.95), mechanical ventilation＞7 d(OR 95% CI: 2.71-129.15), and duration of parenteral nutrition＞14 d(OR 95% CI: 1.83-76.52) were independent risk factors for HAI.ConclusionThe incidence of HAI in VLBWI is high and risk factor is multiple. Respiratory tract is the main infection site, gramnegative bacillus is the most frequently isolated pathogen,more attention should be paid to fungal infection.