Background: Chinese herb tuber fleeceflower root can enhance learning and memory ability and anti-cerebral ischemia ability in rats, while 2,3,5,4′-tetrahydroxystilbene-2-O-β-D-glucoside, the main effective component of tuber fleeceflower root, has very strong brain-protecting effects such as anti-oxidation and anti-aging. Objective: To observe the amelioration of learning and memory disorder after administration of 2,3,5,4′-tetrahydroxystilbene-2-O-β-D-glucoside in mice with learning and memory disorder caused by scopolamine. Design: Randomized controlled trial. Setting: Institute of Pharmacology, Xuanwu Hospital of Capital University of Medical Sciences. Materials: The experiment was conducted in the Institute of Pharmacology, Xuanwu Hospital of Capital University of Medical Sciences, between February 2000 and May 2000. Totally 50 male Kunming mice were recruited and randomized into 5 groups: normal control group, model group, positive control group, 2,3,5,4′-tetrahydroxystilbene-2-O-β-D-glucoside 0.03 g/kg group (low-dose group), and 2,3,5,4′-tetrahydroxystilbene-2-O-β-D-glucoside 0.1 g/kg group (high-dose group). 2,3,5,4′-tetrahydroxystilbene-2-O-β-D-glucoside was an effective component extracted from Chinese herb tuber fleeceflower root in the Department of Pharmacology, Xuanwu Hospital of Capital University of Medical Sciences. Piracetam was the positive control drug. Morris water maze and passive avoidance reflex box were made in the Institute of Materia Medica, the Chinese Academy of Medical Sciences. Methods: Administration was given 5 days before experiment. Tap water was intragastrically grven into the mice in normal group and model group. Piracetam of 0.7 g/(kg.d) was given to the mice in positive control group an 0.03 g/kg of 2,3,5,4′-tetrahydroxystilbene-2-O-β-D-glucoside was given to small-dose group and 0.1 g/kg to large-dose group for 5 consecutive days. Model establishment started 30 minutes after administration in each group on day 6. The same volume of normal saline was intraperitoneally injected into the mice in normal control group and 1 mg/kg of scopolamine was intraperitoneally injected into mice in the other groups. Morris water maze and passive avoidance tests were carried out 20 minters later. Injection dose of model establishment of Morris water maze was 1 mg/kg and that of passive avoidance test was 10 mg/kg. Main outcome measures: 1 Searching distance and time of mice in Morris water maze in each group. 2 Latency and entry-times of mice in passive avoidance test in each group. Results: All the 50 mice were recruited in the experiment, and 49 of them entered the result analysis, 1 mouse in model group died because of intraperitoneal hemorrhage when scopolamine was injected. 1 Results of Morris water maze test: Searching time and distance were significantly shortened in large-dose group as compared to those in model group [(77.814±46.492), (99.319±38.104)s; (1 370.914±917.40), (1 808.77±869.36) cm; P all < 0.05]. 2 Results of passive avoidance test: The number of entry times in small-dose group and large-dose group was significantly decreased compared with that in model group [(0.00±0.00), (0.00±0.00), (0.8571±2.267) times, P < 0.01], and the latency had an extended tendency [(300±0.00), (300±0.00), (269.71±80.128) s ]. Conclusion: 2,3,5,4′-tetrahydroxystilbene-2-O-β-D-glucoside given to mice with learning and memory disorder induced by scopolamine can shorten the searching time and distance in Morris water maze and reduce the number of mistake-making times in passive avoidance test. It suggests that it has ameliorative effects on learning and memory disorder.