Effect of adding stevioside ( the extract of stevia rebaudiana ) during biscuit preparation on rheological properties and organaleptic properties of produced biscuits, as well as biological evaluation including rats body weight gain, organs weight, biochemical parameters [glucose, triglycerides, urea, cholesterol, and kidney functions] and histological examination were investigated. Obtained results declared that no significant difference on rheological or organoleptic properties between control and treated samples when adding stevioside at levels of ( 0.025 , 0.050 , 0.075 and 0.1%) to wheat flour. Serum glucose for rats fed on stevioside added before or after baking showed non-significant values from the beginning till the end of the experiment compared to normal control. On the other hand, rats fed on stevioside added befor or after baking showed significant decrease after^, three weeks from starting compared with diabetic control. Serum triglycerides and serum total cholesterol showed non-significant changes between control and tested groups. No significant changes in all the histological parameters are showed when adding steviosoide.