The purpose of this study is to elucidate the existence of adaptive and cross-adaptive response to ultraviolet-C radiation (UV) and ethyl methanesulfonate (EMS) in sarcoma 180 cells. Two assays were employed in this study; cell survival assay and sister chromatid exchange (SCE). The survival of cells pretreated with 2 J/㎡ UV or 2 mM EMS following treatment with high-dose of UV (10, 20 J/㎡) or EMS (10, 20 mM) was higher than the survival of cells treated with high-dose of UV or EMS alone. On the other hand, the pretreatment with UV (1, 2 J/㎡) or EMS (1, 2, 3 mM) did not affect the frequency of SCE induced by subsequently treatment with 7 J/㎡ UV or 10 mM EMS. Considering above results, it is suggested that there are adaptive response and cross-adaptive response to UV or EMS on cell survival, whereas there is not adaptive response to UV or EMS on SCE.