Objective:To investigate the correlation between serum cystatin C (CysC), blood lipids and the risk of intracranial aneurysm (IA) rupture.Methods:Patients with saccular IA admitted to the First Affiliated Hospital of Xinjiang Medical University from December 2017 to May 2019 were enrolled retrospectively. The patients were divided into the ruptured group and the unruptured group. The correlation between CysC, lipids and IA rupture was identified by univariate and multivariate logistic regression analyses. Results:A total of 392 patients were enrolled, including 143 (36.5%) males and 249 (63.5%) females. Two hundred and seventy-eight patients (70.9%) were ruptured IAs, 114 (29.1%) were unruptured IAs. Univariate analysis showed that triglyceride (1.26±0.94 mmol/L vs. 2.12±1.45 mmol/L; t=5.872, P<0.001), apolipoprotein A-Ⅰ (0.95±0.29 g/L vs. 1.08±0.34 g/L; t=3.744, P<0.001 ), CysC (0.63±0.20 mg/L vs. 0.80±0.48 mg/L; t=3.650, P<0.001) level, and the proportions of hypertension (46.8% vs. 61.4%; χ2=6.938, P=0.008), hyperlipidemia (19.4% vs. 48.2%; χ2=32.493, P<0.001) and aneurysm diameter >7 mm (24.4% vs. 41.2%; χ2=11.504, P<0.001) of the ruptured group were significantly lower than those of the unruptured group, while the level of apolipoprotein B was significantly higher than that of the unruptured group (1.07±0.29 g/L vs. 0.99±0.30 g/L; t=2.417, P=0.016). Multivariate logistic regression analysis showed that aneurysm diameter ≤7 mm (odds ratio [ OR] 2.281, 95% confidence interval [ CI] 1.342-3.876; P=0.002), and the serum levels of triacylglycerol ( OR 0.484, 95% CI 0.333-0.705; P<0.001), apolipoprotein A-Ⅰ ( OR 0.248, 95% CI 0.105-0.587; P=0.002) and CysC ( OR 0.130, 95% CI 0.038-0.444; P=0.001) were significantly independently correlated with the risk of IA rupture. Conclusions:CysC, apolipoprotein A-Ⅰ and triacylglycerol are protective markers for IA rupture, and aneurysm diameter ≤7 mmis associated with IA rupture.