At recent the number of livestock is increased and the size of farm has changed to large facilities in Korea. So the livestock facilities have become one of major sources of odor emission. The purpose of this study is to analyze the concentration and assessment of odor unit from livestock facilities for cow, dairy, swine and poultry. The eleven odor pollutants such as $H_2S$, ($CH_3$)SH, $(CH_3)_2S$, $(CH_3)_2S_2$, $CH_3N$, $NH_3$, $(CH_3)_2N$, $(CH_3)_3N$, butyric acid, valeric acid and isovaleric acid, measured for assessment of the odor concentrations from livestock facility. As the results, it is found that the major matters of odor from livestock facilities were $NH_3$ and $H_2S$. The highest concentration of $NH_3$ is measured as 15 ppm at henhouse and $H_2S$ is measured as 858 ppb at penpig facilities. In the comparison of the average odor unit from livestocks, it is found that the highest odor unit was from swine and the lowest odor unit was from cow facility. So odor unit from swine facilities was 12 to 30 times higher than the odor unit from cow facilities.