Objective:To investigate the clinical significance of changes in heparin binding protein(HBP), procalcitonin (PCT) and prealbumin (PA) levels in the early diagnosis of intracranial infection in patients with brain tumors after surgery.Methods:The clinical data of 160 patients with brain tumors who underwent surgical treatment in the Second Affiliated Hospital of Xuzhou Medical University from January 2015 to December 2020 were retrospectively analyzed. And 80 cases of intracranial infection after surgery were classified as the infection group. According to the severity of infection, patients were divided into 33 cases in the mild infection group, 36 cases in the moderate infection group, and 11 cases in the severe infection group; 80 cases without postoperative intracranial infection were classified as the non-infection group. All enrolled members were tested for HBP, PCT, PA at time points of 0 h before surgery, 12 h after surgery, 3 d after surgery, and 6 d after surgery. Receiver operating characteristic (ROC) curve was used to evaluate the diagnostic efficacy of intracranial infection in patients with brain tumors after surgery.Results:The levels of HBP and PCT in the infected group were higher than those in the non-infected group before and after surgery at all time points (all P < 0.05). The level of PA in the infected group was lower than that in the non-infected group (all P < 0.05). The levels of HBP and PCT in both groups at various time points after surgery were higher than those before surgery (all P < 0.05), which showed a decreasing trend over time. The level of PA of both groups at all time points after surgery was lower than that before surgery (all P < 0.05), which showed a trend of first decreasing and increasing and then decreasing over time. The preoperative HBP level in the severe infection group [35.45 ng/ml (23.61 ng/ml, 59.44 ng/ml)] was higher than that in the mild infection group [12.51 ng/ml (5.11 ng/ml, 19.92 ng/ml)] and the moderate infection group [22.22 ng/ml (16.49 ng/ml, 27.55 ng/ml)], and differences were statistically significant ( Z = 41.167, 19.105, both P < 0.05). The preoperative PCT level in the severe infection group [1.50 μg/L (1.27 μg/L, 2.44 μg/L)] was higher than that in the mild infection group [0.53 μg/L (0.25 μg/L, 0.85 μg/L)] and the moderate infection group [0.90 μg/L (0.47 μg/L, 1.42 μg/L)], and differences were statistically significant ( Z = 36.167, 14.875; both P < 0.05). The preoperative PA level in the severe infection group [159.22 mg/L (141.61 mg/L, 191.79 mg/L)] was lower than that in the mild infection group [215.91 mg/L (195.21 mg/L, 239.90 mg/L)] and the moderate infection group [194.48 mg/L (178.40 mg/L, 207.60 mg/L)] ( Z = 35.955, 19.567, both P < 0.05). The levels of HBP and PCT before operation were positively correlated with the degree of infection ( r = 0.637, 0.485, both P < 0.01). The preoperative level of PA was negatively correlated with the degree of infection ( r = -0.576, P < 0.01). The preoperative single index detection showed that the maximum the area of the curve (AUC) of postoperative intracranial infection in patients with brain tumors predicted by PA was 0.808 (95% CI 0.741-0.874). The highest specificity of intracranial infection in patients with brain tumors predicted by HBP was 96.3%. The AUC of postoperative intracranial infection in patients with brain tumors predicted by the combination of the three tests was 0.892 (95% CI 0.839-0.944), which was greater than that predicted by other single indicators, and the sensitivity was the highest (86.3%). The AUC of postoperative intracranial infection in patients with brain tumors diagnosed by PCT at 12 h after surgery was maximum [0.804 (95% CI 0.734-0.874)] when predicted by other single indicators. The highest specificity of postoperative intracranial infection in patients with brain tumors diagnosed by HBP was 98.6%. The AUC of postoperative intracranial infection in patients with brain tumors diagnosed by the combination of the three tests was 0.895 (95% CI 0.840-0.950), which was greater than that diagnosed by other single indicators, and the highest sensitivity was 85.0%. Conclusion:The levels of HBP, PCT and PA can provide a reference for the early diagnosis of postoperative intracranial aseptic inflammation in patients with brain tumors. The combined diagnosis of HBP, PCT and PA can better diagnose the postoperative intracranial infection in patients with brain tumors.