Objectives : The objective of this study is to investigate the suppressing effect of the cervi pantotrichum cornu pharmacopuncture on the expression of iNOS mRNA and production of NO in synoviocytes from artificially arthritis-induced mice. Methods : In vitro test, synoviocytes extracted from a knee joint of a mouse were cultivated, and the herbal extract of cervi pantotrichum cornu($0.4mg/m{ell}$, $0.6mg/m{ell}$, $0.8mg/m{ell}$, and $1.0mg/m{ell}$) was added into the wells of synoviocytes to suppress the expression of iNOS mRNA and production of NO. In vivo test, each ten mice were allocated into three groups; Normal group, CIA-elicitated group(CIA), and group treated with cervi pantotrichum cornu pharmacopuncture after CIA elicitation(CCA). The extract of cervi pantotrichum cornu was injected into the acupoint of $SP_{10}$ to observe the changes of foot thickness in mice and the suppression of MIF, TNF-$alpha$, NF-${kappa}B$ p65, and iNOS. Results : In vitro test, the expression of iNOS mRNA and production of NO were dose-dependently decreased in the wells of synoviocytes treated with PMA. In vivo test, the suppression of MIF, TNF-$alpha$, NF-${kappa}B$ p65, and iNOS was clearly shown in the pieces of the synovial joint treated with the extract of cervi pantotrichum cornu. The foot thickness also decreased dose-dependently. Conclusions : It is speculated that the cervi pantotrichum cornu pharmacopuncture can be applicable to the therapy of rheumatoid arthritis by suppressing the expression of iNOS mRNA and production of NO.