Objective To understand the distribution characteristics and antimicrobial resistance of Serratia marcescens (S. marcescens), provide evidence for rational application of antimicrobial agents as well as prevention and control of S. marcescens infection. Methods Electronic medical record data of hospitalized patients who were detected S. marcescens at Shengjing Hospital of China Medical University from 2017 to 2023 were collected and analyzed statistically. Results From 2017 to 2023, a total of 388 strains of S. marcescens were detected, 238 strains (61.34%) were isolated from male patients and 150 strains (38.66%) from female patients; 95 strains (24.49%) were from children under 14 years old, 144 strains (37.11%) were from adults under 60 years old, and 149 strains (38.40%) were from elderly people over 60 years old, 33 strains were from newborns, accounting for 8.51% of the total strains and 34.74% of strains from children. From 2017 to 2023, the detection rate of S. marcescens remained relatively stable with small fluctuations (0.52%-0.60%), the detected specimens were mainly sputum (38.92%), with department of surgery (39.69%)being the most and department of gynecology and obstetrics being the least(1.55%). From 2017 to 2023, the resistance rate of S. marcescens to cefazolin was the highest (97.42%), fo-llowed by cefuroxime (71.13%), tetracycline (59.02%), cefamandole (57.47%), amoxicillin/clavulanic acid (44.59%), ampicillin/sulbactam (42.53%), cefoxitin (34.02%), chloramphenicol (15.21%), and furantoin (14.18%). The resistance rates of S. marcescens to quinolones from 2017 to 2023 were 0.52%-8.25%. Polymyxin-resistant and tigecycline-resistant S. marcescens emerged in 2022 and 2023, respectively. Conclusion In clinical practice, antimicrobial agents should be selected rationally for the treatment of S. marcescens infection, and S. marcescens should be focused in monitoring as well as infection prevention and management, so as to prevent and control the occurrence of S. marcescens infection.