Objectives To study the effect of D.L-Glyceraldehyde(D.L-GA) on preserve blood glucose concentration.Methods Heparinized blood from volunteers and diabetic patients was added into tubes in which contained or without D.L-GA. After incubation for various times. Plasma glucose and other common clinical biochemical tests were determined with biochemistry analyzers.Results Glucose concentration was effectively preserved in whole blood specimens by 4 0mmol/L D.L-GA. Blood glucose concentration in the specimens treated with 8 0mmol/L D.L-GA were stable and most routine biochemical tests were uninterfered by the presence of D.L-GA.Conclusions D.L-GA effectively preserves glucose concentration in whole blood specimens within 8h. Specimens treated with 8.0mmol/L D.L-GA are suitable for analysis of clinicial routine biochemical tests including determination of blood glucose concentration.