To analyze the CT features of lung metastasis of senile colorectal cancer，and to explore the risk factors affecting its metastasis，in order to provide a certain value for the clinical diagnosis and treatment of lung metastasis of colorectal cancer.

The clinical data of 105 elderly patients with colorectal cancer admitted from June 2018 to June 2019 were retrospectively analyzed. All patients were followed up for 3 years after discharge and underwent regular CT review. According to whether the patients had lung metastasis，they were divided into lung metastasis group（n=24 cases）and control group（81 n=cases）. SPSS 23.0 statistical software was used to analyze the data. The measurement data of normal distribution are expressed as（

All 105 elderly patients with colorectal cancer were followed up for 3 years，and 24 of them developed lung metastasis（22.8%）. The CT features of elderly patients with lung metastasis of rectal cancer were multiple lesions with multiple solid nodules < 3 cm in diameter and uniform enhancement inside the lesions. Univariate analysis and multivariate logistic regression analysis showed that colorectal cancer，Dukes C stage，adenocarcinoma and CEA levels were high risk factors for lung metastasis in elderly colorectal cancer.

Colorectal cancer，Dukes stage C，adenocarcinoma，and elevated CEA levels are high risk factors for lung metastasis in elderly patients with colorectal cancer. Moreover，CT features are often multiple lesions with multiple solid nodules < 3 cm in diameter and mostly uniform enhancement inside the lesions，which is worthy of attention in clinical diagnosis and treatment of colorectal cancer patients.