The increasing of diabetic prevalence encouraged scientists to discover sweetener  as sugar substitution. Stevia is a perenial shrub (known as Stevia rebaudiana) of the aster family that has been used for hundred of years to sweetening. Stevia is a natural, non caloric, sweet tasting plant known for its pleasant sweet taste without leaving bitter aftertaste.  The leaves contain primarily stevioside and rebaudioside. Both have potential for  antihyperlicemic and blood pressure lowering effect. Besides its empirical long-use without any reported toxicity in Latin America and Asia, Japan also enhanced its widespread use. Negative side effects of Stevia has not been seen yet. Stevioside and rebaudioside are not genotocsic in vitro or in vivo in animal models and  the genotocicity of steviol and some of its oxidative derivats  in vitro are not expressed in vivo. (The study is an assessment derived from 30 of the report studies/review collected from international journals). The objective is to evaluate the biochemical, to study the effect and safety of stevia herb as well as to support  its use as sugar substitution particularly for diabetic patients.