The purpose of this study is to investigate the microbiological characterization of pathogenic bacteria isolated from trauma patients after Wenchuan earthquake in 2008. Most infections were identified in the patients over 60 years of age, with an incidence rate of 78.5%, and more infections in wound (43.3%) and respiratory tract (37.1%) sites were identified. A total of 97 non-duplicated clinical pathogens were isolated from 91 trauma patients. Of those pathogens, 62 (63.9%) were Gram-negative bacilli, 23 (23.7%) were Gram-positive cocci, 9 (9.3%) were fungi, and 3 (3.1%) were anaerobes, such as Clostridium perfringens. The distribution spectrum of pathogens isolated from trauma patients after earthquake was different to that from non-earthquake trauma patients in our hospital at the same time. The most prevalent pathogenic isolates were Escherichia coli (15.4%), Acinetobacter baumannii (14.4%), Staphylococcus aureus (12.3%), Burkholderia cepacia (11.3%), and Enterococcus spp. (9.3%). The drug susceptibility results showed that most of the Gram-negative bacilli, except for Pseudomonas aeruginosa and Burkholderia cepacia, were susceptible to imipenem, but resistant to the first- and the second-generation cephalosporins. Most of the Gram-positive cocci were susceptible to vancomycin, linezolid, and Synercid/dalfopristin. Characteristics of pathogenic bacterium isolated from trauma patients after earthquake have been demonstrated which play an important role in the appropriate treatment of infections.