Abstract: The single screw dry extruder(EXT-155G)processing experiments were carried out to investigate the urea's effect on the melamine residue in extruded soybean powder with three level of urea 0%(control group),0.5% and 1.0% respectively.The melamine residue in the samples of different groups before and after extruded for the mean T test by SPSS 17.0.The randomized trial results showed that the melamine residue in the experiments(supply with urea)before and after extruded has significant difference(P0.01).In summary,it suggested that soybean powder with urea in the dry extrusion process can increase the melamine residue.