Abstract: Objective To explore the significance of liver biochemical indexes in the diagnosis of coal-burning arsenism with receiver operating characteristic(ROC)curve analysis.Methods Totally 307 arsenic poisoning patients and 84 healthy persons with normal liver function were recruited as cases and controls from Xingren county(an endmic area of coal-burning arsenism)in Guizhou province in January 2014.Biochemical methods were used to measure liver biochemical indexes of the participants.The significance of the liver indexes in the diagnosis of coal-burning arsenism was evaluated by calculating the area under the ROC curve (AUC).Results Compared with those in the controls,the concentration of total protein (TP) and albumin (ALB) and the ratio of albumin and globulin (A/G)in the cases were all decreased (all P < 0.01),while the activity of alkaline phosphatase (ALP) and the level of total bile acid (TBA) were increased (both P < 0.05).The activity of γ-glutamyl transpeptidase (γ-GT) in the cases with moderate and severe arsenism were higher than that in the controls (P < 0.05).For the cases with mild arsenism,the AUC of ALB,A/G,TBA,TP and ALP are 0.79,0.71,0.64,0.63,and 0.60 and all the AUC values are statistically significant (all P < 0.05);the sensitivity of the indexes ranks with a decreasing order of A /G,ALP,ALB,TBA,and TP.For the cases with moderate arsenism,the AUC of ALB,A/G,TBA,TP,ALP,and γ-GT are 0.86,0.81,0.76,0.67,0.61,and 0.59 (all P < 0.05) and the sensitivity of the indexes ranks with a decreasing order of ALB,TBA,A/G,TP,ALP,and γ-GT.For the cases with severe arsenism,the AUC of ALB,A/G,TBA,TP,ALP,and γ-GT are 0.89,0.87,0.79,0.72,0.67,and 0.63 (all P < 0.01) and the sensitivity of the indexes ranks with a decreasing order of ALB,TBA,A/G,TP,ALP,and γ-GT.Conclusion Serum ALB,TBA and A/G ratio may be significant biomarkers for the early diagnosis of arsenism and could be predictors for the severity arsenism.In addition,TP,ALP and γ-GT may be adopted as references for auxiliary and grading diagnosis of arsenism.