Objective: To analyze the epidemiological characteristics of acute paraquat(PQ)poisoning in children in southwest Shandong, and the risk factors for pulmonary interstitial fibrosis. Methods: This retrospective study was performed on the clinical data of children with acute PQ poisoning admitted from January 2013 to December 2017 in 12 hospitals in southwest Shandong.All participants were divided into pulmonary interstitial fibrosis group and no pulmonary interstitial fibrosis group on the basis of the chest CT 14 days after poisoning.The epidemiological characteristics and risk factors of pulmonary interstitial fibrosis were analyzed. Results: During the study period, a total of 307 children with acute PQ poisoning were admitted to 12 hospitals, of which 61 (19.87%) were suffering from acute PQ poisoning.Forty-nine cases with complete clinical data were analyzed, including 26 male and 23 female patients poisoned by oral.The age distribution ranged from 8 months to 14 years.Poisoning mainly occured from July to September of each year.The mortality of acute PQ poisoning was 8.2%(4/49), and the incidence of pulmonary interstitial fibrosis in survival patients was 44.4%(20/45). Statistical differences (P<0.05) were found between the pulmonary interstitial fibrosis and no pulmonary interstitial fibrosis, with regard to the times of blood purification, the time from poison exposure to blood purification, the application rate of glucocorticoids, the concentration of PQ in urine, the pediatric critical illness score, the time from poison exposure to gastric lavage, the white blood count at admission, serum creatinine, arterial blood lactate, PaO₂, PaCO₂, and PaO₂/FiO₂; however, there was no significant difference in the proportion of blood purification treatment, the mode of blood purification treatment, alanine aminotransferase, aspartate aminotransferase, urea nitrogen, creatine kinase and troponin.Stepwise logistic regression analysis showed that the time from exposure to poison to gastric lavage(OR=0.683, 95%CI 0.210-2.222)and to blood purification(OR=0.0133, 95%CI 0.004-0.042), the times of blood purification(OR=2.862, 95%CI 1.450-5.648), concentration of PQ in urine(OR=1.435, 95%CI 1.085-1.898), and the use of glucocorticoids(OR=0.190, 95%CI 0.048-0.757) were the risk factors for pulmonary interstitial fibrosis(P<0.05). Conclusion Early gastric lavage and blood purification, increasing the frequence of adminitrating purification appropriately, using low-dose glucocorticoids can reduce the incidence of pulmonary interstitial fibrosis of children with acute PQ poisoning.