Abstract: Objective To investigate the impacts of different storage time of venous blood on biochemical indicators such as total bilirubin （TBIL）, direct bilirubin （DBIL） and alanine aminotransferase （ALT）. Methods 120 cases of health examination in our hospital from January 2017 to June were selected, and the blood biochemical indexes of immediate time, place 4 h, 12 h and 24 h were detected by automatic biochemical analyzer. Results The levels of Ca²⁺, K⁺ and Na⁺ in the blood placed for 24 h were significantly higher than those at immediate time, while K⁺ , P^-and Cl^- were significantly lower than those at immediate time （P<0.05）; The levels of Ca²⁺ and K⁺ in place 12h was significantly higher than those at immediate time （P<0.05）; The blood aspartate aminotransferase （AST） and alkaline phosphatase （ALP） in place 24h blood were significantly higher than those at immediate time, while TBIL, alanine aminotransferase （ALT）, urea nitrogen （BUN） and β2 microglobulin （β2-MG） were significantly lower than that at immediate time （P<0.05）; The blood TBIL and BUN in place 12 h blood were significantly lower than those at immediate time, and the AST was significantly higher than that at immediate time （P<0.05）; There were no significant difference in DBIL, glutamyl transpeptidase （GGT）, albumin （ALB） and serum creatinine （Scr） among immediate time, place 4 h, 12 h and 24 h （P>0.05）. Conclusion The time of different placement of venous blood has an effect on some biochemical indexes, therefore, we should pay attention to control the time of specimen placement in clinical, and reduce the error of test Results .

Key words: Venous blood, Time of placement, Biochemical indicators