PURPOSE: A feed additive composition containing fermented red ginseng meal as an active ingredient, and a producing method thereof are provided to use by-products obtained from a red ginseng extraction process. CONSTITUTION: A feed additive composition contains 10-30% of fermented red ginseng meal, 5-30% of soybean meal, 5-30% of wheat bran, 1-15% of starch, 1-15% of molasses, and 1-15% of corn powder. The fermented red ginseng meal is obtained by injecting bacillus subtilis to red ginseng meal. The feed additive composition is secondly fermented using probiotics selected from the group consisting of lactobacillus acidophilus, aspergillus oryzae, saccharomyces cerevisiae, and streptococcus thermophilus.본 발명은 발효홍삼박을 유효성분으로 하는 사료 첨가제 조성물 및 그 제조방법에 관한 것이다.