Abstract: Objective To investigate the level and relevant factors of organophosphorus pesticides (OP) exposure among pregnant women during pregnancy in Shenyang municipality of Liaoning province,and to provide references for implementing intervention measures.Methods Totally 249 healthy pregnant women hospitalized for childbirth were recruited at Affiliated Central Hospital of Shenyang Medical College from March 2011 through March 2012.Urine samples of the women before delivery were collected for detections of 5 nonspecific dialkylphosphates (DAPs) metabolites of OP insecticides with gas chromatography-mass spectrometry (GC-MS).The relevant factors of OPs exposure during pregnancy were investigated with a questionnaire survey.Results The detection rates were 95.6%,93.6%,95.6%,88.8%,and 6.8% for dimethylphosphate(DMP),dimethyl thiophosphate(DMTP),diethylthiophosphate (DEP),diethylthiophosphate (DETP),and diethyldithiophosphate(DEDTP),respectively.The geometric means (GM) of urinary metabolites were 13.78 μg/L for DMP,6.50 μg/L for DMTP,5.56 μg/L for DEP,and 4.00 μg/L for DETP.The pregnant women aged ≥30 years had significantly higher concentrations of dimethyls (DMs) than those <30 years old (P<0.05).The women who never used pestcides at home had significantly lower concentrations of DMs and DAPs than the others (P<0.05).The results of multivariate stepwise regression showed that the women aged ≥30 years,living in suburb,using pesticide frequently during pregnancy were more likely to have higher urinary DAPs than other women (P<0.05 for all).Conclusion Pregnant women in Shenyang municipality had high OPs exposure and the OPs metabolite levels were associated with age,residential place,and frequency of household pesticide use during pregnancy.