This research was aimed to utilized from baladi orange pomace (Citrus sinensis) as by-products from juices factories which causes some environmental problems  in processing  low cup  calories cakes.  Wheat flour 72% extraction was substituted with powdered orange pomace  at different  three levels i.e.  5, 10 and 15%. Effect of orange pomace on physical, chemical, textural characteristics and microstructure properties of  cup cakes were  determined. A gradual decrease in moisture, ether extract, carbohydrates,  while fiber and ash contents were increased  with the increase in concentration of powdered orange pomace.  with substitution of 15 % orange pomace to cake batters  and cake formulae  was  negatively effect on physical characteristics namely , pH, line spread, and volume cm³,  texture profile and volume measurements. Results of scanning electron microscope showed that substitution with  15 % orange pomace caused undesirable  changes in the structure of starch granules, gluten matrix and the gas cells  comparing  with the other cup cake formulae. Results of sensory evaluation indicated that  cup  cake  formulae  containing 5% and 10% orange pomace have the highest scores for taste ,odour, height , crumb colour and crust colour in compared with cup cake formula with 15 % orange pomace. So, substitution wheat flour 72 %  with orange pomace powder up to 10 % in   processing  low calories cup cake is recommended .