Abstract: Objective To evaluate the comorbidity factors by Charlson Comorbidity Index and hematopoietic cell transplantation comorbidity index,assess their relationships with chemotherapy toxicity,and discuss the suitability of the two index. Methods Total 66 cases of first acute myeloid leukemia aged 40 or above in our hospital between 2010 and 2014 were enrolled into this study.Charlson Comorbidity Index and hematopoietic cell transplantation comorbidity index were used to evaluate the comorbidity factors.Chi-square test or Fisher's exact test and Spearman's rank correlation analysis were performed to analyze the correlations.Logistic regression model was employed to predict the relative risk. Results The incidence of severe infection in patients with high comorbidity score(CCI ≥ 4,29 cases or HCT-CI ≥ 3,22 cases) was higher than that in patients with lower comorbidity score(CCI<4,10cases or HCT-CI<3,17 cases),the difference was statistical significant(P<0.05).But the high comorbidity score was not obviously correlated with the occurrence of other severe conditions.Multivariate analysis showed that high CCI score was still associated with an increased risk of severe infection in the CCI group(OR=4.385,95%CI:1.134-16.924;P<0.05),however,in the HCT-CI group,high HCT-CI score(≥ 3) was not obviously related to the severe infection after chemotherapy,but age(≥ 60 years) was associated with an increased risk of severe infection(OR=4.597,95%CI:1.002-21.146;P<0.05). Conclusion The patients with AML with high CCI or HCT-CI are easily to catch a severe infection after chemotherapy;Charlson Comorbidity Index is more suited for the prediction of comorbidity factors in patients with AML.