Abstract: OBJECTIVE To explore the significance of C reactive protein(CRP) in the detection of pathogenic bacteria in patients with aplastic anemia complicated with infections, so as to provide evidence for clinical diagnosis and prevention and control of infections in such patients. METHODS The clinical data of 52 cases of patients with aplastic anemia complicated with infections in our hospital from Jan. 2012 to Dec. 2015 were retrospective analyzed, whose blood, urine, sputum were cultured, and the distribution of pathogenic bacteria were detected. At the same time, the serum levels of CRP in the two groups were detected, and the changes of serum CRP levels in patients with different pathogenic bacteria were compared. RESULTS In this group of 52 patients, a total of 78 strains of pathogenic bacteria were detected, among which the rate of gram-negative bacteria was the highest(58.97%), mainly of Escherichia coli (20.51%),Pseudomonas aeruginosa (15.38%) and Acinetobacter baumannii (14.10%). The composition ratio of gram-positive bacteria was 28.21%,of which the Staphylococcus aureus(11.54%) was the highest. The composition ratio of fungi was 12.82%, with Candida albicans composition ratio (7.69%) the highest. There were 14 cases of gram-positive bacterial infections,28 cases of gram-negative bacterial infections,6 cases of fungal infections,4 cases of bacterial and fungal infections, and there was significant difference in serum CRP levels in infected patientsbefore and afer treatment(P<0.05). CONCLUSION Aplastic anemia patients complicated with infection were most commonly infected with gram-negative bacteria, and there is a significant difference in the level of serum CRP in patients with different pathogenic bacteria infection, which has significant clinical significance and application values on the differential diagnosis and treatment of infections.