Abstract: Objective To compare the clinical characteristics and drug resistance of diabetes mellitus (DM) patients with Klebsiella pneumoniae bloodstream infection (KPBSI) at different hemoglobin A1c (HbA1c) control levels.Methods DM patients with KPBSI who were treated in the Affiliated Hospital of Xuzhou Medical University from January 2017 to December 2021 were enrolled and their clinical data were retrospectively analyzed. According to their HbA1c control levels, they were divided into three groups:group A (HbA1c<7%), group B (7% ≤ HbA1c<9%), and group C (HbA1c ≥ 9%). The three groups were compared for general information, basic diseases, initial laboratory indexes, complications, 30-day mortality and antimicrobial resistance.Results Compared with groups A and B, increased patients in group C had a body temperature ≥ 38.5℃ (n=21, 95.5%) and liver abscess (n=9,40.9%)(P<0.05). Compared with group A, group C showed increases in white blood cell count12.2(9.1, 14.7)×10⁹/L, neutrophil count10.7(8.0, 13.9)×10⁹/L, and hemoglobin(127±23)g/L levels in the early stage of bacteremia. The proportion of patients in group C who were resistant to meropenem was lower than that in group A and group B, and the proportion of patients resistant to aztreonam and levofloxacin was lower than that in group A (P<0.05).Conclusions In KPBSI patients, HbA1c control levels are associated with initial leukocyte count, neutrophil count levels, and metastatic abscess complications. Patients with higher HbA1c levels showed lower antibiotic resistance to meropenem, levofloxacin, and aminotransomide.