-Amylase (EC 3.2.1.1) is a class of enzymes that is capable of digesting these glycosidic linkages found in starches , catalyzing the cleavage of the -1, 4-glucosidic linkages between glucose molecules in starch.With the beginning of new frontiers in biotechnology, the spectrum of - amylase application has expanded into many fields, such as clinical, medicinal, and analytical chemistries. - Amylase has many applications in the industrial process such as in the food, textiles and paper and Because of the importance of -amylase; the current study`s aims are : Isolation and identification of Bacillus stearothermophilus from different soil samples, Production, purification ,characterization of some properties of thermolabile -amylase and molecular cloning of -amylase gene from Bacillus stearothermophilus in E. coli then investigate the possible expression of -amylase gene in the transformed cells.