Abstract: Objective: To investigate the distribution and constitution of pathogens in a burn unit.Methods: The identification data of bacteria isolated from our burn unit in a 5 year period were analyzed in terms of years, seasons, ages and gender.Results: The constituent ratio of S. aureus was gradually increased and ranked the first in infectious pathogens of the burn unit. Staphylococcus was comparatively prevalent in spring, P. aeruginosa distributed evenly in four seasons, and other bacteria were pervalent in the summer. Gram positive cocci and P. aeruginosa were predominant in old patients, Enterobacter and Serratia were frequenters in children, and the constituent ratio of some bacteria in female were much higher than that in male in certain period.Conclusion: It is important to know the constitutional changes and distribution characters of pathogens for a better sanitation, infection prophylaxis and treatment in burn units.