Ifosphamide has a wide anticancer activity. The activity of Ifosphamide can be improved and its toxicity can be lowered by enhancing the relative specific accumulation in the tumor regions. The aim of this work was to develop Eudragit RS100 based Ifospphamide microsponges(MS). Oil in oil emulsion solvent diffusion method was used for the preparation of Ifosphamide sustained release Eudragit RS100 MS. MS were characterized for their encapsulation efficiency, production yield and drug polymer interaction, PXRD and Particle size visualized by scanning electron microscope (SEM). The results showed that all prepared MS were spherical in shape with several pores on their surfaces. The production yield was in 84±0.14. Entrapment efficiency was in 85% and particle size was (1 µm ± 0.03 µm and 5µm ± 0.21 µm). Fourier transform infrared revealed that there is no chemical interaction between Ifosphamide and Eudragit RS100. The results demonstrated that ifosphamide with Eudragit RS100 was successfully formulated.