【Objective】The suitable dose range for irradiation-induced mutation of seashore paspalum, Paspalum vaginatum Swartz, was studied to provide theoretical foundation and technical reference for seashore paspalum breeding. 【Method】 The stolons of two cultivars of seashore paspalum Sea Isle 2000 and Platinum were treated under four doses of ⁶⁰Coγ irradiation at 0, 40, 50, 60 Gy.The optimal mutagenic doses and growth characteristics were examined.【Result and conclusion】 The stolon survival rate of seashore paspalum decreased with the increase of irradiation dose. The suitable irradiation dose ranges were 41.38-49.75 Gy and 54.07-64.89 Gy for Platinum and Sea Isle 2000 respectively. Irradiation significantly reduced leaf width of the two varieties and internode length of Sea Isle 2000, indicating that the texture of the seashore paspalum had been obviously improved. It is concluded that 40-60 Gy irradiation dose is suitable for irradiation mutation breeding of seashore paspalum.