A selective medium for Corynebacterium michiganense pv. michiganense (SMCMM) was developed. The composition of the medium was as follows: peptone 5g, yeast extract 3g, K2HPO4 2g, KH2PO4 0.5g, MgSO4⋅7H2O 0.25g, glycerol 20g, LiCl 5g, K2Cr3O7 80mg, NaN3 2mg, nalidixic acid 20mg, cycloheximide 40mg, 70% tetrachloroisophthalonitrate hydrate 3mg, agar 15g in one liter of distilled water. Recovery of C.m. pv. michiganense on SMCMM from the pure culture was higher than on D2 medium by Kado et al. and CNS medium by Gross et al. C.m. pv. michiganense grew well on SMCMM and developed to the characteristic fresh yellow colonies. The colony forming efficiency of the general microorganisms on the tomato leaves and soil were very low compared with nutrient agar medium.