The present invention relates to a manufacturing method of a feed additive composition for improving a meat quality of a mart which comprises: a step of manufacturing a mixture by mixing 2-20 weight% of sulphur, 10-40 weight% of vitamin C, 0.1-4 weight% of chrome, 0.1-3 weight% of magnesium, 0.05-0.4 weight% of zinc and 1-9 weight% of vegetable fat and oil base on the standard of final feed composition； a step of shaping a pellet by injecting a mixture which is previously manufactured to a perforated sheet； a step of manufacturing a particle which has a size of 0.5-2mm by pulverizing a shaped pellet； a step of coating the particle which is previously manufactured with 35-60 weight% of vegetable fat and oil； wherein the vegetable fat and oil in the mixing step has more than 40°；C of melting point； and has more than 55°；C of melting point in the coating step. The feed additive composition which is manufactured with the method thereof is capable of maintaining a high stability inside the intestinal canal of the mart； containing high concentration of sulphur, and mineral, vitamin C which are an inorganic substance； reducing a supplying cost by having a small supplying amount to the mart； having a small production expense by having a mass producing. The high quality Korean native beef can be produced by supplying the composition to a Korean native cattle by mixing the composition with the feed thereby effectively being used as a feed additive for the mart. Additionally, the income of the farm is increased by drastically improving the quality of meat of the mart thereby securing a competitiveness against FTA through the high quality mart. [Reference numerals] (AA) START； (BB) A step of manufacturing a mixture by mixing 2-20 weight% of sulphur, 10-40 weight% of vitamin C, 0.1-4 weight% of chrome, 0.1-3 weight% of magnesium, 0.05-0.4 weight% of zinc and 1-9 weight% of vegetable fat and oil base on the standard of final feed composition； (CC) Step (1)； (DD) A step of s
