In Ethiopia, Pastoralists represent approximately 10% percent of the country population, and approximately 40% of the land area of Ethiopia is considered to be under pastoral production system. Consequently, Pastoralists contribute a significant amount to the national economy. However, the pastoral production system and in particular the food security and livelihood situation is highly threatened due to various factors. This review is, therefore, shows the definition and concepts of food security and livelihood diversification. Besides, it elaborate factors affecting food security and effect of livelihood diversification on food security in pastoral area of Ethiopia. Methodologically, this manuscript is based on intensive literature review of published materials such as books, articles and extra scholar materials. It was displayed that household head sex, family size, age of household head, educational level of household head, crop production and agricultural technology (use of chemical fertilizer and pesticides, improved seeds), livestock ownership and number, dependency ratio, distance from market center, access to credit and developmental agents visit had found to be significant in determining household food security. Livelihood diversification basically influenced by push and pull factors. In general, higher the level of the household livelihood diversification, results with, the more food secure of the households. In the future, concerned agents should focus on boosting educational level, family planning and awareness creation to reduce dependency ratio, credit serves and visit by development agents for livelihood diversification and thereby food security. Keywords: Ethiopia, Factors, Food security, Livelihood diversification and Pastoral area DOI: 10.7176/FSQM/98-01 Publication date: June 30 th 2020