Objectives: To determine the frequency and microbiological characteristics of bacteria causing septic shock in patients with positive blood culture results. Methods: Cross-sectional descriptive study. Results: Total 100 patients diagnosed with septic shock had positive blood culture results at Nghe An General Friendship Hospital from January 2020 to December 2020. The mean age was 67.06 ± 16.42 years old. There were 57 patients ≥ 65 years old, accounting for 57%, more common than patients < 65 years old (43 patients with a rate of 43%). The proportion of Gram-negative bacteria (66%) was higher than Grampositive bacteria (34%). The respiratory tract infection (52%) was the most common source, followed by the intra-abdominal infection (23%) and the urinary tract infection (10%). E. coli was the most common pathogen (32%), followed by S. aureus (26%) and K. pneumoniae (11%). Among patients with diabetes and COPD, the most common pathogens were E. coli, S. aureus and Enterococcus faecalis. Most of the antibiotic groups were been resistant, especially cephalosporin antibiotics from 37.5% to 82.6%. Amikacin, fosmycin, vancomycin and linezolid groups were susceptible to bacteria. Conclusion: E. coli and S. aureus were two common pathogens in patients with septic shock. In particular, E. coli, S. aureus and Enterococcus faecalis were the common agents of septic shock among patients with diabetes and COPD. Amikacin, Fosmycin, Vancomycin and Linezolid groups were still susceptible to bacteria. Key words: septic shock, E. coli, S. aureus.