This study was conducted on Housing Development Program Financing System: Performance and Challenges in Oromia Regional State- in Ethiopia. The study focused on, the amount of fund raised from different alternative sources of finance as per the plan, the affordability of housing cost, and sustainability of housing program financing system as possible variables of the study. In this study I preferred to evaluate the performance of housing program financing system and to identify related challenges that affect the sustainability of the program at affordable cost to provide affordable housings for medium & low income households in on Oromia regional state in Ethiopia. The finding of study identified the major problems in the system which affect the sustainability of integrated housing development program and its financing system in Oromia regional state. At the end this study included some possible alternative solution ideas that can improve the gaps in housing development financingsystem.