Salmonella Typhimurium is a virulent pathogen for human and animal. We studied serotypes, biochemical characteristics, and antimicrobial resistance of S. Typhimurium isolated from diseased pigs in Gyeongbuk province over 1998 to 2008. One hundred sixteen isolates were identified as S. Typhimurium by biochemical characteristics and serotypes from 90 farms. The biochemical characteristics of S. Typhimurium isolates was production of $H_2S$, indole-negative, fermentation of mannitol, dulcitol, sorbitol, inositol, rhamnose, and maltose, and ornithine decarboxylase. At antimicrobial susceptibility test, the majority of isolates were highly susceptible to amoxicillin/clavulanic acid, cefepime, ciprofloxacin, while were highly resistant streptomycin, cephalothin, enrofloxacin, nalidixic acid, apramycin, chloramphenicol, tetracycline. The isolates were divided into 65 resistant patterns and 47 of the isolates were shown as a DT104 ASSSuT resistant phenotype.