Objective: To observe the correlation between the condition of patients with acute cerebral infarction and serum beta 2-microglobulin (beta 2-MG) levels. Methods: Patients with acute cerebral infarction and healthy physical examinees selected for the prospective study were included into the cerebral infarction group and control group, respectively. Clinical data were collected and the patients' condition were evaluated, and then the contents of the beta 2-MG, high sensitivity C reactive protein (hsCRP), interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-alpha (TNF-alpha), intercellular cell adhesion molecule-1 (ICAM-1) and soluble CD40 Ligand (sCD40L) in serum were tested. Results: The contents of serum beta 2-MG, hsCRP, IL-6, IL-8, TNF-alpha, ICAM-1, sCD40L in patients with acute cerebral infarction were obviously higher than those in cases of the control group. The severer the condition of the disease was, the higher contents of serum beta 2-MG, hsCRP, IL-6, IL-8, TNF-alpha, ICAM-1 and sCD40L became. The greater the volume of cerebral infarction was, the higher the contents of serum beta 2-MG, hsCRP, IL-6, IL-8, TNF-alpha, ICAM-1 and sCD40L were. The content of serum beta 2-MG was positively associated with the contents of hsCRP, IL-6, IL-8, TNF-alpha, ICAM-1 and sCD40L. Conclusions: The level of serum beta 2-MG was abnormally elevated in the patients with acute cerebral infarction. The level of serum beta 2-MG can evaluate the severity of disease, infarction size and the degree of inflammation reaction in patients with acute cerebral infarction.