Abstract: The neuroendocrine and immune systems formed intra-system and inter-system communication circuitry by similar ligands and receptors, which maintained the homeostasis of body. As potential immunomodulators, neuropeptides participated in various kinds of immunity-regulating functions. The distribution of neuropeptide somatostatin （SS） and its receptors in the immune systems and their immunoregulatory functions on the immunity were reviewed, so as to provide theoretical foundation for exploring the immunoregulatory mechanism of SS.