To observe the analgesic effect of Jiedu Tuoyin Decoction (JTD) and its influence on reproduction of morphine dependence rats. JTD is composed of Rhizoma Coptidis, Radix Rehmanniae, Radix Aconiti, Radix Astragali, Radix Codonopsis, Ramulus Uncariae cum Uncis, etc..Sixty rats were randomly allocated to six groups: normal saline group (Group A), morphine and normal saline group (Group B), morphine and clonidine group(Group C),morphine and low dosage of JTD group (Group D), morphine and moderate dosage of JTD group (Group E) and morphine and high dosage of JTD group (Group F).Content of ? endophin(? EP) in hypothalamus and plasma, substance P (SP) content in ganglion nodosum(GN) and nucleus tractus solitarii(NTS) and serum levels of sexual hormones were examined.(1) ? EP content in hypothalamus of morphine dependence rats was lower and SP content in ganglion nodosum and nucleus tractus solitarii was higher than that of normal rats (P