The analgesic effect of ginsenosides or morphine was determined following intrathecal (i.t.) administration in rat tail-flick test. The effects of intrathecal co-administration of ginsenosides with morphine on the development of opioid tolerance and dependence were also examined using rat tail-flick test and naloxone-pre-cipitated withdrawal, respectively. Administration of ginsenosides (i.t.) produced a weak antinociception in a dose-dependent manner. Administration of morphine (i.t.) also produced antinociception in a dose-dependent manner. The $ED_50$ was $1.20;{mu}g;(1.14~1.29;{mu}g)$. However, the acute co-administration of $200{mu}g$ ginsenosides with 0.1-1.0${mu}g$ morphine did not show additive effect on morphine induced analgesia in rat tail-flick test. I.t. co-administration of 200 ${mu}g$ ginsenosides with 10 ${mu}g$ morphine for 7 days inhibited development of tolerance induced by 10 ${mu}g$ morphine in rat tail-flick test, although i.t. co-administration of 50 or 100 ${mu}g$ ginsenosides with morphine was without effect. I.t. co-administration of 200 ${mu}g$ ginsenosides for 7 days also partially attenuated the development of morphine dependence as assessed by naloxone-precipitated withdrawal. In conclusion, these results suggest that i.t. administered ginsenosides produce a weak antinociception in rat tail-flick test and also prevent opioid tolerance and attenuate opioid dependence in chronic treatment with morphine at the spinal sites.