Objective To investigate the changes in pCREB protein expression in the distal cerebrospinal fluid contacting neurons induced by chronic morphine dependence and withdrawal. Methods Twenty-four SD rats of both sexes were randomly divided into 3 groups (EM>n/EM>=8):the control group;the chronic morphine dependence group;the chronic morphine abstinence group. The methods of intraventricular injection of CB-HRP and CB-HRP/pCREB double-labeling in immunohistochemistry methods were used to observe the expression of pCREB in the distal cerebrospinal fluid contacting neurons. Results The CREB protein was activated in the distal cerebrospinal fluid contacting neurons induced by chronic morphine dependence and withdrawal, the numbers of CB-HRP double-labeling neurons in the two experimental groups were significantly elevated 223.0±61.5 and 213.0±50.6 respectively； when compared to the control expression of pCREB protein (P<0.01). Chronic morphine dependence and withdrawal showed no differences on the expression of pCREB protein (EM>P/EM>>0.05).Conclusion The distal cerebrospinal fluid contacting neurons were involved in the formation of chronic morphine dependence and withdrawal by activating the CR