One of the effective methods in plant breeding is the mutation breeding. Recently new techniques in mutation breeding has risen by using heavy ion beam irradiation. The local rice variety, Pare Bau was used to study the effect of heavy ion beam for aromatic rice improvement. Dry seeds of rice were irradiated at dose of 10 Gy Argon ion. Selected mutants from M2 were planted on M3 generation to check their stability in growth performance and early flowering. Results show that one M3 mutant line showed significantly lower plants height and larger percentage of fertile grain in comparison to control. Therefore, these results indicate that heavy-ion irradiation may provide useful genetic resources for high yield breeding on early generation of mutant line.