To observe the clinical effects of Dan Hong Injection on cerebral infarction and to explore its action mechanism.Methods: A total of 202 patients with cerebral infarction were randomly divided into control group and treatment group.Control group took oral aspirin and intravenous drip in adr + mannitol; the treatment group took Dan Hong Injection in addition to abovementioned treatments; after 2 weeks (W) treatment,we measured nitric oxide synthase (NOS) and superoxide dismutase (SOD) content,determined blood rheology indicators and regional cerebral blood flow (rCBF),nerve dysfunction scoring and compared the curative effect.Results: Compared with that of the control group),Dan Hong Injection could significantly increase SOD and NOS,improve rCBF and neural function defect score.Conclusion: Dan Hong Injection can decrease the lipid peroxidation after cerebral infarction,remove oxygen free radicals,improve regional cerebral blood flow,therefore have ideal efficacy on cerebral infarction.