Objective ·To investigate the association of exposure to parabens, a class of common used preservatives in food, drugs and personal care products, with pulmonary function in preschool children. Methods ·A total of 136 preschool children aged 5?7 years old were recruited from Shanghai children's Hospital,Shanghai Jiao Tong University School of Medicine from August 2019 to January 2020. Baseline information such as children's age, height, body mass index (BMI), and annual family income were collected. Urine samples were taken, and the concentrations of five kinds of urinary paraben were detected by high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS), including methyl 4-hydroxybenzoate (MeP), ethyl 4-hydroxybenzoate (EtP), propyl 4-hydroxybenzoate (PrP), butyl 4-hydroxybenzoate (BuP) and benzyl 4-hydroxybenzoate (BzP). The forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC, peak expiratory flow (PEF), forced expiratory flow between the 25th and 75th percentile of forced vital capacity (FEF25-75) were measured by using pulmonary function instrument. Multiple linear regressions were conducted to examine the associations between paraben exposure and pulmonary function indexes in children. Results ·In the 136 preschool children, the average age and BMI were (5.76±0.84) years and (15.78±2.96) kg/m2 respectively, 59 (43.4%) were males, and 13 (9.6%) were obese children. The detection rates of MeP, EtP, PrP, BuP and BzP were 97.8%, 86.8%, 99.3%, 77.9% and 11.8%, respectively; the median creatinine-adjusted levels of MeP, EtP, PrP, and BuP were 36.12, 3.88, 1.50 and 0.06 μg/g, respectively. After adjusting age, sex, height, BMI, preterm birth, and annual family income, the results of multiple linear regressions suggested significantly negative associations between MeP and FVC (β=-0.018, 95%CI-0.035?-0.001, P=0.044), PrP and FEV1 (β=-0.032, 95%CI-0.051?-0.013, P=0.013), BuP and FVC (β=-0.018, 95%CI-0.034?-0.002, P=0.038), as well as BuP and FEV1 (β=-0.021, 95%CI-0.041?-0.001, P=0.047). Conclusion ·Preschool children in Shanghai may be widely exposed to parabens, and exposure to parabens is negatively associated with child pulmonary function.