Alcoholic dementia is increasingly becoming both a severe medical issue and a social problem; the unknown overall mechanism is the bottleneck for effective intervention and treatment of alcoholic brain injury. As the primary structure for the release, transmission of neurotransmitter and information integration between neurons, synapse plays a significant role in performing the advanced function of brain, such as learning and memory. Based on the neurobiological principles of synaptic structure and function, the changes in process and efficiency of synaptic transmission and information integration stressed by alcoholic molecular were reviewed in comparison with the normal process. The molecular mechanisms for alcoholic brain damage in learning and memory abilities were systematically discussed from the levels of synaptic morphology, material components, and signal transduction, respectively, and the repairing strategies for the damaged synaptic structure were proposed accordingly. Hopefully, this review could provide a deep insight into understanding the molecular mechanism of alcoholic brain damage, and draw ideas for the memory-enhancing peptides development.