Women may suffer from various kinds of symptoms during menopause. These may include physical and psychological changes; osteoporosis is the major health problem in this phase in addition to cardiovascular disease. This research aimed to study the effect of soy flour Protein on some biological parameters in ovariectomized rats including density and structure of bones, estrogen and thyroxin FSH,LH, PRO,TSH hormone. The  study was performed on female Albino rats that divided in to six groups, one group was sham operated and fed standard diet. The other five groups were  the ovarictomized one group fed on the standard diet, while remaining four group  were  fed with soy flour in percents of (25,50,75,100 %) of meal protein. After nine weeks femour bone structure and density . The body weights of food intake, Food Efficiency Ratio (FER), Protein Efficiency Ratio (PER), internal body organs were also measured Alkaline phosphates enzyme, estrogen and FSH, LH, TSH, Prolactine hormones were determined.. The results showed that soy flour consumption improved the nutritional status FER, PER, bone density, bone structure and decreased in alkaline phosphates enzyme level, but increased estrogen. Therefore, the researcher recommends postmenopausal women to eat soy flour, soybeans and soy products which are rich in isoflavons that improve estrogen hormone level, hence reduces osteoporosis, heart and cardiovascular diseases risks.