Red　yeast　rice　is　a　traditional　Chinese　medicine　and　food　that　has　been　purported　to　color　food,　ferment,　and　lower　cholesterol.　In　order　to　study　the　antioxidative　capacity　of　red　yeast　rice　and　the　effects　on　electrical　potential　difference　(EPD)　of　12　acupuncture　meridians,　the　pH　value,　oxidation　reduction　potential　(ORP),　ABTS,　FRAP,　T-SOD,　and　particle　size　distribution　of　red　yeast　rice　were　analyzed.　20　volunteers　were　recruited　and　randomly　divided　into　two　groups,　the　red　yeast　rice　group　(10　g　red　yeast　rice　and　40　g　water)　and　control　CK　group　(50　g　water).　The　left　12　acupuncture　meridians＇　EPD　was　real-time　monitored.　Samples　were　taken　at　the　10th　minutes.　The　whole　procedure　continued　for　70　minutes.　It　is　shown　that　the　pH　value　of　the　red　yeast　rice　was　4.22,　the　ORP　was　359.63　mV,　the　ABTS　was　0.48　mmol　Trolox,　the　FRAP　was　0.08　mmol　FeSO4,　the　T-SOD　was　4.71　U,　and　the　average　particle　size　was　108　nm　(7.1%)　and　398.1　nm　(92.9%).　The　results　of　12　acupuncture　meridians＇　EPD　showed　that　the　red　yeast　rice　can　significantly　affect　the　EPD　of　stomach,　heart,　small　intestine,　and　liver　meridians.