Scutellaria baicalensis is known as a herbal medicine with anti-inflammatory and anti-oxidative activities. However, effect of Scutellaria baicalensis on lupus pathogenesis that is characterized by overproduction of proinflammatory cytokines and abnormalities in regulation, function, and interaction of immune cells remains unclear. We investigated effects of Scutellariae radix methanol extract (SBMeOH) on the production of proinflammatory cytokines and abnormal activation of T cells in vitro in pristane-induced lupus BALB/c mice. These results demonstrated that SBMeOH significantly decreased the LPS-stimulated production of $TNF-{alpha}$, IL-6, and IL-10 by splenic and peritoneal macrophages and IL-6 and IL-10 by splenocytes from pristane-induced lupus mice. SBMeOH significantly downregulated the Con A-stimulated overproduction of IL-6, IL-10, and $IFN-{gamma}$ by splenocytes from pristane-induced lupus mice. Also, SBMeOH significantly attenuated the Con A-induced expression of CD4+ T cells and CD69+CD4+ T cells but not CD8+ T cells in pristane-induced lupus mice. Our findings indicate that SBMeOH may ameliorate lupus pathogenic inflammation and autoimmunity via downregulation of proinflammatory cytokine production and abnormal activation of T cells.