Abstract: A process for making PU air permeable nubuck sheets includes coating a separable release substrate material such an cloth, plastics, or paper with a polyurethane (PU) resin preparation before disposing the same in an impregnation tank to allow the PU resin to congeal into a sheet of minute pores attached to the release substrate material. The release substrate material together with the sheet is soaked in a wash tank to rinse off residual dimethyformamide (DMP) A beck surface of the release substrate material is coated with a water soluble resin (which may later dissolve in water and then be rinsed off) and the release substrate material is put into an oven to dry and then removed to a grinder for processing into a nubuck sheet with the feel and visual characteristics of real nubuck. The nubuck sheet is washed in a wash tank to rinse off the water soluble resin, dried, subjected to surface finishing, and than separated from the release substrate material to obtain a PU air permeable nubuck sheet.