An object of the present invention is to provide a golf ball resin composition having a high resilience, flexibility and high fluidity. The present invention provides a golf ball resin composition having a bending stiffness (M21-30) ranging from 600 kgf/cm2 to 5,000 kgf/cm2 within a bending angle from 21° to 30°, a rebound resilience (R) of 50% or more, a slab hardness (Shore D) ranging from 40 to 65, a melt flow rate (190° C., 2.16 kgf) of 1.0 g/10 min or more, and a resilience index value ((M21-30)0.5×(R/100)3) of 8.5 or more.