The changes of contaminants and odor corresponding to anaerobic maturation process of piggery slurry were investigated by applying the additives, such as different kinds of complex microorganism products and deodorants containing microorganism activating agents. The pHs during 20-day anaerobic maturation were operated stably without great change regardless of the additives, although they were rather lower in the case that the additives were contained than the case that they were not contained. The effects of removing CODcr, $NH_3-N$, T-N, and T-S in case that the additives were not contained, were not so great during the 20-day operation and so it would be difficult to remove the organic materials and nitrogen ingredients simply with anaerobic maturation process. However, in case of anaerobic maturation process that the additives were contained, their average removal rates were improved with the values of $49\%,;63.5\%,;48.5\%,;and;30.7\%$ for above each of items, even if the 20-day of short-term maturation period was applied. Especial1y, odor intensity with the additives was lowered continuously during the operation period and it had more than two times of lowering effect compared to that without those.