Objective To understand the distribution and antimicrobial resistance of bacteria isolated from patients in department of hematology in China, and provide scientific basis for rational clinical antimicrobial use in patients with infection from department of hematology. Methods According to the technical program from China Antimicrobial Resistance Surveillance System (CARSS), distribution and antimicrobial resistance of clinically isolated bacteria from patients in department of hematology in 2021 were analyzed by WHONET 5.6 software. Results A total of 74 300 non-repetitive clinically isolated strains were collected from patients from department of hematology in CARSS hospitals, including 53 970 (72.6%) Gram-negative bacteria and 20 330 (27.4%) Gram-positive bacteria. Escherichia coli was the most frequently isolated bacteria (n=16 051, 21.6%), followed by Klebsiella pneumoniae (11 214, 15.1%), Pseudomonas aeruginosa (6 071, 8.2%), Staphylococcus aureus (4 768, 6.4%) and Enterococcus faecium (3 600, 4.8%). The most common specimen source was blood (24.6%), followed by sputum (24.0%) and urine (16.6%). The resistance rates of Escherichia coli to imipenem and meropenem were 4.4% and 4.3%, respectively, and those of Klebsiella pneumoniae to imipenem and meropenem were 10.8% and 11.5%, respectively. Resistance rates of Pseudomonas aeruginosa to imipenem and meropenem were 16.7% and 12.8%, respectively. Resistance rates of Acinetobacter baumannii to most tested antimicrobial agents were 14.3%-27.0%, except polymyxin B, minocycline and tigecycline, which were less than 10%. The resistance rate of Haemophilus influenzae to ampicillin was 64.5%. Among Staphylococcus aureus and coagulase negative Staphylococcus, isolation rates of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase negative Staphylococcus (MRCNS) were 28.8% and 82.1%, respectively. No Staphylococcus aureus strains were found to be resistant to vancomycin and linezolid. The resistance rates of Enterococcus faecium and Enterococcus faecalis to vancomycin were 3.2% and 0.2%, respectively, and that of Streptococcus pneumoniae to penicillin was 1.6%. No Streptococcus strains were found to be resistant to vancomycin and linezolid. Conclusion Gram-negative bacteria are the major bacteria isolated from department of hematology. Carbapenem-resistant Klebsiella pneumoniae, linezolid-resistant Staphylococcus and linezolid-resistant Enterococcus should be paid more attention. Monitoring of antimicrobial resistance of pathogenic bacteria should be strengthened, and antimicrobial agents should be used rationally.