Objectives This study was carried out to find out the anti-osteoarthritic effects of Ma-hwangbujaseshin-tang (Mahuangfuzixixintang) on the monosodium iodoacetate (MIA)-inducedosteoarthritis rats. Methods Osteoarthritis was induced by injecting MIA (50μl) into the knee joint of rats. Rats were divided into a 3 groups (n=7). The injection did not fit the normal group. A week later, after the injection of MIA, while control group took normal saline 2 ml, the extract of Mahwangbujaseshin-tang (Mahuangfuzixixintang) (MBST) (200 mg/kg) was injected to treated group. After that, we examined hind paw weight bearing ability, functions of liver and kidney, serum TNF-α, IL-1β, IL-6, PGE2, LTB4, TIMP-1, MMP-9 and hematology. Volume of cartilage was measured by micro CT arthrography. Injury of synovial tissue was measured by H & E, Safranin-O immunofluorescence.Results1) DPPH and ABTS free radical scavenging activity of MBST was increased ac-cording to concentration of MBST and total phenolic contents were in high level. 2) In RAW 264.7 cells, ROS production was significantly decreased in MBST (at 10, 100μg/ml) and NO was also decreased but meaningless in MBST (at 100μg/ml). 3) In RAW 264.7 cells, IL-6 production was significantly decreased in MBST (at 100μg/ml) and TNF-α and IL-1βproduction were also decreased but meaningless in MBST (at 100μg/ml). 4) In hind legs weight-bearing measurement, level of weight-bearing was increased. 5) Functions of liver and kidney were not affected. 6) TNF-α, IL-1β, IL-6, PGE2, LTB4, MMP-9 and TIMP-1 production were significantly decreased. 7) In hematology, the levels of neutrophils, mono-cytes were significantly decreased and the levels of white blood cells, lymphocytes were al-so decreased but meaningless. 8) In micro CT-arthrography, cartilage volume was sig-nificantly increased. 9) Histopathologically, injury on cartilage and synovial membrane of MBST group was decreased. Conclusions Based on all results mentioned above, Mahwangbujaseshin-tang (Ma-huangfuzixixintang) is believed to be meaningful for suppressing the progress of osteoar-thritis. And it is related to inhibiting the activity of inflammatory cytokine and injury of volume in cartilage. (J Korean Med Rehab 2014;24(2):65-81)