Alpha amylase is a class of amylases that aid in the breakdown of internal α-1, 4-glycosidic linkages in starch. They are important in various pharmaceutical, food, brewing, paper, chemical and textile industries. The aim of this work was to produce and characterize α-amylase produced by A. niger. A. niger was used to produced alpha amylase in a basal salt medium which was then purified with activated carbon. The effect of pH, temperature, substrate concentration and heat on the produced amylase was investigated. The highest activity of the enzyme was recorded at 40 °C and pH 6.0. The apparent Km value for the enzymic hydrolysis of starch was 0.13mg/ml. Heating at 70 °C greatly affected the activity of the enzyme losing up to 35% of its activity after 5 mins. Physical conditions of heat, pH and concentration of substrate are significant factors which should which affect the activity of enzymes.