Abstract:To observe antagonistic effect of a Chinese materia medica prescription-Quqianling powdered extract on learning and memory impairment caused by exposure to lead.Methods:48 SD rats were randomly divided into six groups,and were fed with 0.05% lead acetate solution consecutively for 28 days except for those of normal control group and Chinese medicine control group.Rats of lead-exposure group were given Sodium Chloride daily by intragastric administration.Rats were given Quqianling powdered extract by intragastric administration in Quqianling treated groups of three kinds of dosage,which was 3.46g/kg,6.93g/kg,13.86 g/kg respectively.By using behavioral indexes such as learning and memory in Morris water maze,influence caused by chronic exposure to low-dose lead and curative effect of Quqianling were observed on rats.Results:chronic exposure to low-dose lead could injury spatial reference memory and spatial working memory,but Quqianling powdered extract could apparently antagonize the toxicity,significantly improve rat's behavior in Morris water maze test.Conclusion:Quqianling powdered extract has significant antagonistic effect on rat's learning and memory impairment caused by exposure to lead.