This reseach was conduct in Adami Tulu Jido Kombolicha district, oromiya regional state, Ethiopia, to assess rural household Food Security Status and its major Determinants. Food security determinants are dynamic, vary from area to area and also its results are area specific but there are scientific standards to measure food security statues. Having a good understanding on the determinats of food security and the way how to measure are very curial for policy makers, govermental and non govermental organizations which are involving in food security issues, to effectively target food security problem and evaluate the effectivenes of food security projects. One of the major factors that affect household food security status in rural areas of Ethiopia in general Adami Tulu Jido Kombolich District in particular was large family size. Food security problem will continue to be a challenge of the wellbeing of human being since the fast population growth ,climate change,soil fertilty problem,high food prices and unemployment problem are not well addressed by policy makers.