Analysis each parameter between ATB and CAP which under the ROC curve. Diagnostic value was appraised by the receiver operating characteristic (ROC) curve. Cutoff value was defined based on the max You-den’s index, which is the value when the difference between the sensitivity and 1-specificity of all points on the ROC curve is the largest. Compared with the WBC count and three of WBC conventional differential count, the CPD parameter achieved a higher AUC, and the maximum area under the AUC curve obtained by combining MNC, MMV, and MMC was 0.99. WBC, white blood cells; NE%, neutrophil percentage; LY%, lymphocyte percentage; MO%, monocyte percentage; NMC, neutrophil mean conductivity; MMV, monocyte mean volume; MMC, monocyte mean conductivity.