Abstract: This paper provides a brief review on cellular and molecular mechanism of microglia involving opiates addiction，also introduces prevention and cure of neuro-immuno suppressive agent on opiates addiction. Opiates addiction brings serious medical and social problems. Most researchers concentrate on opiates′ effects on neurons. Current rehabilitation medicines acting on opioid receptor of neurons have limited efficacy. Neurons are not the only components in central nervous system（CNS）.Although accounting for 10% -15% of CNS cell，the function of microglia has been neglected. Opioid stimulates Toll-like receptor 4（TLR4），which induces microglia activation and inflammatory factors production. As a result，reward signaling pathway is regulated to increase neuron excitability，leading to drug dependence and addiction. The neuromodulatory properties of the immune factors，together with their essential role in neuroinflammation，provide a new framework to understand how neuroimmune system mediates brain function and addiction behaviors.

Key words: opiates, addiction, microglia, Toll-like receptor 4