Aim To investigate the effects of high concentration hydrogen-oxygen mixed gas (HCHOG) on skin blood flow. Methods Using MoorFLPI-2 Laser Speckle blood stream real-time imaging system, the blood flow amount in facial and hand skin before and after the inhalation of HCHOG (66.7% hydrogen gas + 33.3% oxygen gas) were examined in 12 healthy adult volunteers, respectively. Results After 30 minutes of HCHOG inhalation, the facial skin blood flow (FSBF) was increased by 9.7% (P＜0.05) compared with the FSBF before HCHOG inhalation. The dorsum of hand skin blood flow (DHSBF) was increased significantly by 27.1% (P＜0.01) compared with the DHSBF before HCHOG inhalation. Conclusion A short-time inhalation of HCHOG notably enhanced the FSBF and DHSBF in healthy adults, respectively.