Induced mutation is an important tool to increase the genetic variation in breeding program. Kaempferia rotunda was introduced to induce mutation by gamma irradiation for improving its ornamental trait. In vitro young shoots of K.rotunda were used as plant material for acute irradiation at the dose of 0–30 Gy. After irradiation,the LD50 was 16.5 Gy and the explants that were irradiated at the dose of 25 and 30 Gy found no survivors. At 15 and 20 Gy, the height of in vitro M1V1 plants was reduced while number of shoots was not different from the control. Then the irradiated plants were sub cultured on new medium at 4 weeks interval. When cultured to M1V4, the 20 Gy irradiated plants did not survive. The morphology of all irradiated M1V6 plants showed significantly decrease of plant height, leaf length, leaf width, number of leaves and number of roots compared with the control. Increasing in dose of gamma radiation enhanced emergence of variegation in K.rotunda leaves. There were two variegated patterns found from this study; half variegated leaves (HV) and central variegated leaves (CV).