Abstract: OBJECTIVE To investigate the effects of different anti infection methods at different time points on changes of procalcitonin (PCT) and surgical effect in postoperative patients with intracranial aneurysms, so as to rationally use of antibiotics, reduce the incidence of postoperative pulmonary infection, and improve the effect of surgical treatment. METHODS A total of 88 cases cerebral aneurysm patients in the hospital from Dec.2013 to Dec.2015 were selected, and divided into observation group and control group by randomized, single blind extraction method, with 44 cases in each group. In observation group, the patients were immediately treated with anti infection when PCT≥0.5 μg/L, while in control group, anti-infection treatment were carried out after identifying as lung infection. The PCT, CRP and WBC levels of the two groups 3 d after anti-infection treatment were observed, and the pulmonary infection and adverse reactions during the treatment period were compared. RESULTS Prophylactic anti-infection 3d and 5d, there was no significant difference in the two groups of arthritis index of PCT, CRP and WBC. There were 28 cases of patients with PCT≥0.5 μg/L in observation group in postoperative 6 d, and 29 cases in control group. The patients in observation group were given antibiotic treatment, and in control group were continue to observe and were diagnosed of pulmonary infection postoperative 7 d~8 d and given antibiotics anti-infection treatment. The inflammatory indicators of observation group after 8 days were higher than those of the operation in the same group after 6 days (P<0.05), PCT was lower than that of control group at the same time (P<0.05), and postoperative 10 days were less than 6 days after operation and compared with control group (P<0.05). Pulmonary infection was occurred in both groups after treatment. There was only 1 case of pulmonary infection occurred in observation group, and 44 cases in control group, with significant difference (χ²=33.52, P<0.05). The treatment related adverse reaction rate of observation group was 10.71%, which was significantly lower than 34.48% of control group (P<0.05). CONCLUSION Anti infection therapy can reduce the incidence of postoperative pulmonary infection, promote PCT and other inflammatory factors, and achieve the purpose of reducing the mortality rate. According to the PCT level to give anti infection treatment, the curative effect is better.