Brown algae are a large group of multicellular algae including many seaweeds located in many countries including Egypt. Most brown algae live in marine environments, where they play an important role both as food and as habitat. The present study aims to investigate the effect of brown algae (Sargassumsubrepandum) feeding on oxidative stress (OS), antioxidant defense status and bone healthy indices in obese rats. Thirty albino male rats (140±10g per each) were divided into two main groups, the first group (Group 1, 5 rats) still fed on basal diet and the other main group (30 rats) was feed with diet-induced obesity (DIO) for 8 weeks which classified into five sub groups as follow: group (2), fed on DIO as a positive control; groups (3-6), fed on DIO containing 1, 2, 3 and 4% of brown algae powder (BAP), respectively. At the end of the experiment (8 weeks), rats of the obese group recorded 155.07% of the control (normal) group for the body weight. Replacement of corn starch with 1, 2, 3 and 4% BAP induced significant decreasing on body weight of the obese rats which recorded 137.75, 123.87, 107.69 and 94.92% as a percent of control, respectively. Biochemical analysis data indicated that obesity induced a significant increased (p≤0.05) in plasma oxidants concentration (MDA, 59.92%) and significant decreased (p≤0.05) in plasma non-enzymes antioxidant (GSH, -43.16 % and GSSG, -26.22 %), as a percent of normal group. Feeding on 1-4% of BAP induced significant exhibited a significant improvement (p≤0.05) in all of these parameters by different rates. The same behavior was recorded for the bone healthy indices. The amelioration effects were increased with the elevation of the BAP feeding rate. In conclusion,the present data support the possibility of adding brown algae powder by up to 4% to our daily diets as it contains biologically active compounds that