OBJECTIVE: To evaluate the long-term toxicity of Anti-EB-virus oral liquid on beagle dogs, and to provide safety evidences for clinical experiment. METHODS: Of the total beagle dogs, three groups totaled 18 were assigned to receive Anti-EB-virus oral liquid at high (76.41 g/kg), medium (25.47 g/kg) and low dosage (8.49 g/kg), and 6 (blank control group) to receive placebo. The ratio of male to female in each group was 1∶1. The beagle dogs were administered intragastrically with drugs qd, 6 days in a week for up to 26 weeks. All the indicators were monitored and the recovery of the beagle dogs was observed. RESULTS: Dogs in high dose group vomited obviously. Gastrointestinal irritation was also noted in medium dose subgroup, but was less severe than the high dose subgroup. During the recovery stage, one dog in high dose group was strong positive in urinary protein test and one in medium dose group was strong positive in urinary occult blood test. No significant drug associated toxic reactions were noted from beagle dogs' body weight, temperature, appetite, ECG, hematology test, blood biochemical analysis, ophthalmology test, marrow test, routine urianlysis, histopathologic examination, etc. CONCLUSION: The non-toxic dose of Anti-EB-Virus Liquid on beagle dogs was 8.49 g/kg in crude drug.