This study relates to an improved method for the preparation of azodicarbonamide (ADCA). Blowing agents are substances that decompose or vaporize easily at given temperatures to produce large quantities of gases. This property of blowing agents is utilized in the manufacture of various foams and sponges which are characterized by their extensive cellular structure and low ratio of weight to volume. Foam materials, especially plastic foams, have wide application, including such familiar uses as thermal insulation, life jackets, seat cushions, and package fillers. Azodicarbonamide is a well-known blowing agent. It is an organic compound which at between about l60- 200 ˚C evolves into a gas, the principal constituent of which is nitrogen. Modified azodicarbonamides suitable for use as a blowing agent for high molecular substances having low softening points are prepared by oxidizing hydrazodicarbonamide in aqueous suspension by means of hydrogen peroxide in the presence of a bromine compound. By Series of comparative experiments, Factors of influencing the yield of azodicarbonamide are studied, such as reaction time, type of catalyst and the amount of catalyst. Under the optimum process conditions, the yield of ADCA can reach over 95%.