Abstract: Objective To explore the impact of increase of ALT thresholds for blood donors on the pass rates of first-examination and second-examination. Methods The correlations between analysis results of ALT of initial-examination and re-examination with rapid screening methods were determined with linear correlation analysis. The re-examination pass rates were observed by improve rapid screening thresholds based on the above derived equations. Results The initial examination value of ALT was calculated as 1.1886 + 06137×rapid screening value, and the re-examination value was calculated as 1.4018 + 0.4821×rapid screening value. After increasing 5U or 10U of thresholds of rapid screening value, the initial and re-examination pass rate was all 100%. The pass rates of blood donors were significantly increased. Conclusion The Threshold value of ALT in rapid screening of blood donors could be increased by 5 ~ 10 U without affecting the quality of the blood.