Abstract: Objective To assess the role of PL-11 inducers in monitoring platelet function in healthy subjects after taking clopidogrel. Methods The role of PL-11 inducers,ADP and collagen,in monitoring platelet function in healthy subjects after taking clopidogrel was compared with light turbidimetric analysis（LTA） as its reference. Results The platelet function decreased in 25 healthy male young subjects with a mean age of 27.5±3.7 years 6 days after taking clopidogrel.The baseline value for PL-11 inducer collagen,LTA and PL-11 inducer ADP was 65.9%-89.1%（95%PI）,67.2%-86.8%（95%PI）,64.7%-83.6%（95%PI）,respectively.An overlapped value was found before and after taking clopidogrel.ADP was correlated with LTA（r=0.757,P＜0.001） and collagen（r=0.764,P＜0.001）,collagen was correlated with LTA（r=0.521,P=0.009）.The baseline value of LTA was at least 10% lower after taking clopidogrel than before taking clopidogrel,which could thus be used as the criterion for clopidogrel reactivity.ROC analysis showed that the cut-off value for ADP and collagen was 66% and 60.0%,respectively.The sensitivity and specificity of ADP and collagen were 84.6% and 88.2%,69.2% and 70.6%,respectively. Conclusion The sensitivity of ADP is higher than that of collagen in monitoring the platelet function in healthy subjects after taking clopidogrel.The sensitivity of LTA and ADP is interchangeable,and can thus become a classic light turbidimetry for platelet function monitoring.