Inclusion Criteria:  Hospitalized patients over 20 years of age with acute cerebral stroke admitted by medical institutions. Stroke patients diagnosed by medical institutions were treated with the National Institute of Health Stroke Scale; NIHSS) score is 5-15, which is a moderate degree of stroke Able to perform mouthwash. Those who have passed the three-stage swallowing function screening. Those with stable medical condition.  Exclusion Criteria:  Those who of medical institutes in the diagnosis of severe alzheimer.(ICD-10 code： G30.9) Those who severe mental retardation. Those has a history of mental illness. Those has unable to clearly express their wishes. Those has full mouth teeth less than six. Those has in the past more than a month use mouthwash. Those has treatment of the patients with gingivitis and periodontal disease, oral antibiotics or anti-fungal drugs. Those has unable to cooperate or applicable except of assessment tools.