Objective To investigate the effect of Fucong Tang on learning and memory abilities in A PP/PS1 double transgenic mice with Alzheimer's disease (AD).Methods A total of 20 9-month-old APP/PS1 transgenic mice were randomly divided into two groups:one group receiving Fucong Tang 1 mL/d for 8 weeks (Fucong Tang treatment group) and the other group receiving distilled water treatment.The spatial learning and memory abilities of AD mice were tested with Morris water maze,and Aβ plaques were observed by Aβ+GFAP double immunofluorescence staining,the expression of N-methyl-aspartate (NMDA) receptors subunit 2B (NR2B) by immunohistochemistry,and synapses in CA1 by electron microscopy.Results The 1-4 d escape latency of the Fucong Tang treatment group was significantly shorter than that of the control group (P＜0.005); the time spent in the target quadrants and the frequency of crossing the original platform in the Fucong Tang treatment group were significantly higher than that of the control group (P＜0.05).The average optical density of positive NR2B in the Fucong Tang treatment group was higher that of the control group (P＜0.05).After treatment,Aβ plaques volume and the surrounding activated astrocytes reduced in the Fucong Tang treatment group,while there still presented more compact Aβ plaques and more activated astrocytes in the control group.The damage of synapses of Fucong Tang treatment group presented alleviated.Conclusion Fucong Tang could improve the learning and memory abilities of AD mice by reducing compact Aβ plaques and alleviating associated toxic effects on neurons,and further promoting the expression of NR2B and improving synapse structure.