Objective : The purpose of this study is to find out whether Herba Ephedrae, solely used, and Herbal medicine in which this was included, have inhibitory effects of Nitric Oxide(NO). Methods : We tested the inhibitory effects of Nitric Oxide(NO) with Herba Ephedrae and ten kinds of Herbal medicine combined with Herba Ephedrae(Worlbikachul-Tang, 越婢加朮湯; Mahaengkamsuk-Tang, 麻杏甘石湯; Shinbi-Tang, 神秘湯; Mahwangbujaseshin-Tang, 麻黃附子細辛湯; Euiin-Tang, 薏苡仁湯; Galgeun-Tang, 葛根湯; Mahaengeuigam-Tang, 麻杏薏甘湯; Mahwang-Tang, 麻黃湯; Socheongryong-Tang, 小靑龍湯; Gaemagakban-Tang, 桂麻各半湯) on RAW264.7 cells. Results and Conclusions : 1. We carried out MTT assay on Herba Ephedrae and those decoctions including this in order to determine whether they accommodate cotytoxicity. The results were that Worlbikachul-Tang, Mahaengkamsuk-Tang, Mahwangbujaseshin-Tang, Mahaengeuigam-Tang, Mahwang-Tang, Socheongryong-Tang and Gaemagakban-Tang showed no cytotoxicity on RAW264.7 with 0.1mg/ml and 0.5mg/ml dosages of decoctions but displayed cytotoxicity on the cell with 1mg/ml. Solely used Herba Ephedrae, Shinbi-Tang, Euiin-Tang and Galgeun-Tang exhibited cytotoxicity beyond the concentration of 0.5mg/ml. 2. Worlbikachul-Tang, Mahaengkamsuk-Tang, Shinbi-Tang, Mahwangbujaseshin-Tang, Euiin-Tang, Galgeun-Tang, Mahaengeuigam-Tang, Mahwang-Tang and Socheongryong-Tang showed inhibition of NO production but solely used Herba Ephedrae and Gaemagakban-Tang did not exhibit such reaction.