Corynebacterium was gram positive diphtheroid rods shape bacteria. This bacterium was induce sever disease in immunodeficiency mice such as of Corynebacterium-assoicated hyperkeratosis and pseudotuberculosis. In Korea, we isolated 110 strains of Corynebacterium species from experimental mice and identification with several method. When identified based on 16s rRNA sequence analysis, major isolated Corynebacterium species in Korea were C. mastitidis(46.4%, n=51), C. bovis(23.7%, n=26), C. amycolatum(13.7%, n=15), and C. lowii(15.5%, n=17). When comparing the identified result based on the 16S rRNA sequence with the rpoB gene sequence, biochemical test, and MALDI TOF, rpoB gene method was most similar with 16s rRNA sequence (96.4%), and next MALDI-TOF method(73.1%), biochemical method(15.3%). The low accuracy of MALDI TOF is because C. lowii is not included in the data base. Excluding the results of C. lowii, the accuracy is quite high at 97.4%. C. amycolatum and C. bovis was sometimes isolated from immune deficient nude mice with skin disease. Histopathologically, mild to severe hyperkeratosis with infiltration of lymphocytes plasma and neutrophils and gram positive short rod bacteria found in hyperkeratic area. And we cannot found any disease from C. mastitidis and C. lowii contaminated animals. In conclusion, we isolated 110 strains of Corynebacterium from Korea experimental mice. Different type of identification method showed different diagnostic result. Especially biochemical test has low correlated with 16s rRNA sequence, rpoB gene sequence and MALDI-TOF result. So, it will be important to choose an appropriate identification method for accurate diagnosis of Corynebacterium from mice