Provided are a composition for diagnosing vascular disease including an agent measuring a level of interleukin 12 receptor β2 protein in the blood, and a kit for diagnosing vascular disease including the same. Further, provided is a method of providing information for diagnosing vascular disease, the method including the step of measuring a level of interleukin 12 receptor β2 protein in a blood sample separated from an individual suspected of having vascular disease. Furthermore, provided are a composition for preventing or treating vascular disease including an interleukin 12 receptor β2 activity inhibitor, and a method of screening a therapeutic agent for vascular disease, the method including the step of treating smooth muscle cells with a test agent for vascular disease treatment and measuring an expression level of interleukin 12 receptor β2. According to the present invention, when interleukin 12 receptor β2 is used as a biomarker for vascular disease, in particular, myocardial infarction or unstable angina, vascular disease, of which diagnosis has been performed only by angiography, can be diagnosed using blood in a rapid non-invasive economic manner. Accordingly, the early diagnosis of vascular disease is possible, since the disease has been diagnosed based on subjective symptoms after the appearance of ischemic symptoms with development of the disease. The promise of early diagnosis, prevention and treatment is realized.