Carbohydrates are digested in in vivo gastrointestinal hydrolysis system in the body. To investigate glycemic evaluation of carbohydrate digestion, a lot of in vivo study in the literature, in vitro glycemic study to research postprandial glucose composition with biochemical hydrolysis systems for carbohydrates hasn’t been met. In this study, it was investigated glycemic evaluation by using postprandial glucose after digestion of the bread species from different countries such as the United States, Sweden, and Germany with our constructed biochemical hydrolysis system at in vitro conditions. The assays of GI and GL values of these bread species were carried out with the methods based on spectrophotometric. GI and GL values of American white bread (AWB), Sweden white bread (SWB), German white bread (GWB) were calculated by using Turkish white bread (TWB) as reference carbohydrate. AWB, SWB, and GWB have lower GI values than TWB. GL values were also determined for each bread species by using spectrophotometric biochemical in vitro hydrolysis system because the value indicated for consumption of a foodstuff. TWB had higher GL value than the other bread species. GL values of all bread samples were bigger than 20.