Objective: To investigate the pharmacodynamics and acute toxicity of Duodongan Oral Solution. Methods: The test of walking time and raising the front limbs of mice Step down test were used to observe the improvement of Duodongan Oral Solution on the spontaneous activity inhibition and memory acquisition disturbance of mice. Results: Duodongan Oral solution could obviously inhibit the spontaneous activity of mice, and its action is strengthened with the increase of dosage. The step down test showed that the oral solution could prolong the latent peroid and decrease the error rate in 5 minites, which indicated that the drug obviously improved memory acquisition disturbance. The acute toxic test indicated that the maximum tolerance dose is 159 times as much as the clinical dose a day. Conclusion: This oral solution has much low toxicity, and is safety for oral administration.