Abstract: OBJECTIVE To observe diagnostic value of C-reactive protein (CRP) detection in senile bronchial children and respiratory tract infection in elderly patients, so as to provide a reference basis for clinical prevention and treatment in the future. METHODS Eighty six elderly patients with senile bronchial asthma admitted and treated in the hospital from Feb. 2013 to Mar. 2014 were selected as research subjects, including 45 patients with asthma combined with bacterial infections, and 41 patients suffered from asthma combined with virus infections, and another 44 healthy persons undergoing health check-ups during the same period were selected as control group. The total numbers of blood cells of patients in the three groups were observed, and data were analyzed by SPSS 15.0. RESULTS C-reactive protein level and total number of white blood cells of patients in bacterial infection group were significantly higher than those of patients in virus infection group and control group (P＜0.05). The abnormality rates of C-reactive protein and white blood cells of patients in bacterial infection group were 93.3% and 84.4%, significantly higher than 26.8% and 12.2% of patients in virus infection group (P<0.05). CONCLUSION The serum CRP may be used as one of indicators for early diagnosis of asthma combined with infection, its level may reflect the severity of the illness, contributing to clinical identification of bacteria and virus infection, and it may provide important reference basis for clinical medication, delivering higher application value.