Abstract： Objective To investigate the expression and distribution of α7-nicotinic acetylcholine receptors (α7-nAChR) on rat hippocampal microglial cells. Mehtods Mixed primary glial cells obtained from the cerebral cortex of 1-day-old rats were cultured for 7-9 days, and the microglial cells were purified. The expression of α7-nAChR at the protein and mRNA levels on the microglia cells was detected using double immunolabeling with anti-CD11b/c antibody and RT-PCR. respectively. Results The resting microglial cells harvested from mixed primary glial culture presented with ramified surface covered with spines, which may serve as a unique feature for identifying microglial cells. A band of 450-bp corresponding to α7-nAChR was specifically amplified by RT-PCR.Double immunolabeling showed colocalization of α7-nAChR and CD11b/c on the cultured hippocampal mcrioglial cells. Conclusion α7-nAChR can be normally expressed in rat hippocampal microgiial cells in in vitro culture.