Gestational diabetes mellitus (GDM) has many adverse effects on pregnant women and fetuses. At present, no prediction marker for GDM in early pregnancy is accepted. There is still a lack of recognized early predictors. This study was designed to identity valuable biomarkers for GDM.This was a prospective observed cohort study. 140 pregnant women were recruited in early pregnancy, and followed up to 6 weeks postpartum. Glucose challenge test and 75g oral glucose tolerance test were performed after 24 weeks of pregnancy, and GDM was diagnosed according to the latest ADA standard. Urinary samples were collected in the first (<12 weeks), second (24~28 weeks) and third (32~weeks) trimester of pregnancy. Urinary proteomics and metabolomics were analyzed by ultra-performance liquid chromatography tandem mass spectrometry. 15 cases of GDM women and 50 cases of control women were used for longitudinal analysis; 15 cases of GDM women and 15 cases of age matched control women were used for difference analysis.