The understanding of the organization of postsynaptic signaling systems at excitatory synapses has been aided by the identification of proteins in the postsynaptic density (PSD) fraction, a subcellular fraction enriched in structures with the morphology of PSDs. Here we described an efficient way to isolate the crude synaptosome, presynaptic fraction, and PSD fraction. It helps to identify the location of synaptic protein and find the potential synaptic complex.