Objective To discuss whether the capillary whole blood glucose (CBG) test can be used in glucose screening test (GST) for gestational diabetes mellitus (GDM) compared to the venous plasma glucose (VPG) method, and to determine the cutoff value of CBG. Methods This was a self-control test. The 50-g oral GST was conducted among 1 557 pregnant women between 24-28 weeks. Every woman was measured CBG and VPG at the same time and same arm. Three hundred and forty women underwent 100-g 3-h oral glucose tolerance test (OGTT). Receiver operation curve (ROC) was used to determine the potential cutoff level of CBG and VPG. Diagnose criteria of GDM was based on NDDG criteria. OGTT diagnosed GDM and VPG ≥ 7. 8 mmol/L were used as golden standard for ROC. Results There was good relationship between CBG and VPG ( P ＜ 0.01 ). Correlation coefficient was 0. 86. The value of CBG was lower than VPG. The statistical and high-sensitivity cutoff values were 7. 4 mmol/L in CBG and 7. 8 mmol/L in VPG when GDM was used as golden standard. Cutoff value of CBG was 7. 0 mmol/L when VPG≥ 7. 8 mmol/L was used as golden standard. The pregnant outcomes of positive cases of three thresholds had no significant differences. But it was better in case of the pregnant woman when the CBG value was more than 7. 4 mmol/L. Conclusion CBG can be used in GST, the threshold of CBG was suggested as 7. 4 mmol/L. CBG test was more convenience and effective than VPG test.