Objective: To explore the longitudinal association between organophosphate esters (OPEs) exposure and blood pressure in children, so as to provide a reference for identifying the effects of OPEs exposure on child health. Methods: A total of 404 children from the Beijing Child Growth and Health Cohort (PROC) were enrolled using a case cohort study design, baseline physical examination, urine collection, questionnaires survey were administered in 2018 and follow up surveys in 2019-2020 and 2023. Participants were divided into case group ( n =140) and control group ( n =264) according to the observation of new onset of high blood pressure during the follow up period. High performance liquid chromatography tandem mass spectrometry was used to detect diethyl phosphate (DEP)，bis (2-chloroethyl) phosphate (BCEP)，bis (1-chloro-2-propyl) phosphate, (BCIPP), diphenyl phosphate(DPHP), dibutyl phosphate (DnBP), bis (1,3-dichloro-2-propyl) phosphate(BDCIPP), bis(2-butoxyethyl) phosphate(BBOEP), bis (2-butoxyethyl) 2-hydroxyethyl phosphate (BBOEHEP), 4-hydroxyphenyl diphenyl phosphate (4-OH-TPHP). Generalized linear mixed models and Quantile g computation models were developed to analyze the longitudinal associations between OPEs individual/mixed exposure and blood pressure in children. Results: The detection range of 9 OPEs metabolites,including DEP, BCEP, BCIPP, DPHP, DnBP, BDCIPP, BBOEP, BBOEHEP and 4-OH-TPHP at three time points (baseline, first follow up and second follow up) were 27.7%-92.1%, 24.0%-99.3% and 39.2%-90.9% respectively. Without adjustment for covariates such as gender, age, body mass index, Tanner stage, parental education, and monthly household income, and family history of hypertension, the increase of BDCIPP concentration and mixed exposure of OPEs may reduce children s systolic blood pressure( β= -0.85，-2.40，95%CI=-1.69--0.01，-3.30--1.50，P <0.05). After adjusting for the covariates, the longitudinal association of individual OPEs or mixed exposure with pediatric BP was not statistically significant ( P >0.05). Conclusion Children are commonly exposed to OPEs, and although no significant longitudinal associations are observed between exposure to OPEs and blood pressure among school aged children in Beijing, it is recommended that child exposure should be minimized whenever possible.