Objectives: The purpose of this study is to investigate the effects of Daedon($LR_1$) Supplementation and Eumgok($KI_{10}$) Draining on changes of cerebral blood flow in normal rats. Methods : Regional cerebral blood flow(rCBF) and mean arterial blood pressure(MABP) in normal rats are observed, and those mechanisms were also investigated with pre-treatment of indomethacin (IDM) and methylene blue(MTB) each. Results : In this study, $LR_1$ supplementation and $KI_{10}$ draining elevated level of rCBF after 30 min, but MABP level was lowered at 30 min, then recovered toward normal level. Pre-treatment with indomethacin (IDM), an inhibitor of cyclooxygenase, inhibited increase of rCBF effectively, and pre-treatment with methylene blue(MTB), an inhibitor of guanylate cyclase, also inhibited increase of rCBF levels. On the other hand pre-treatment with IDM or MTB did not affect MABP levels. Conclusions : In conclusion, these results suggest that $LR_1$ supplementation and $KI_{10}$ draining can increase rCBF, and the mechanisms are thought to be related to both of cyclooxygenase and Guanylate cyclase pathways.