Objective To evaluate the measurement uncertainty of endocrine test items by"top-down"method.Methods The"top-down"method in the technical report of CNAS-CL01-G003:2021"Medical Laboratory-Evaluation and Expression of Measurement Uncertainty"was used,collecting the laboratory's internal quality control data and the external quality assurance results of Beijing Clinical Laboratory Center from 2019 to 2021.To evaluate the measurement uncertainty of 11 endocrine tests including free triiodothyronine(FT3),total triiodothyronine(TT3)and free thyroxine(FT4).Results The relative expanded uncertainties of 11 endocrine test items in laboratory were FT3:12.658％,TT3:13.372％,FT4:10.468％,total thyroxine(TT4):32.382％,thyroid stimulating hormone(TSH):8.594％,estradiol(E2):18.656％,follicle-stimulating hormone(FSH):14.650％,luteinizing hormone(LH):29.384％,progesterone(PRO):28.806％,prolactin(PRL):13.810％and testosterone(TESTO):31.610％.At the normal concentration level,the relative expanded uncertainties were FT3:12.424％,TT3:12.462％,FT4:8.606％,TT4:14.130％,TSH:12.536％,E2:19.586％,FSH:14.382％,LH:23.400％,PRO:38.346％,PRL:16.014％and TESTO:39.352％.The relative expanded uncertainties at high concentration levels are FT3:13.882％,TT3:14.096％,FT4:11.040％,TT4:8.614％,TSH:7.782％,E2:14.366％,FSH:13.436％,LH:14.804％,PRO:11.574％,PRL:17.742％,TESTO:39.322％.The relative extended measurement uncertainty of TT4,LH near low concentration levels,PRO near low and normal concentration levels,and TESTO near three concentration levels was higher than the target uncertainty(25％),and the remaining items are less than the target uncertainty.Conclusion The quality control data in the laboratory can reflect the measurement uncertainty of 11 endocrine detection items including FT3,TT3 and FT4 in Abbott i2000SR automatic chemiluminescence immunoassay analyzer,which has important clinical application value.