An apparatus for mounting a curtain airbag cushion, the apparatus including an intermediate connection tab and a strap sewn onto a curtain airbag cushion, a mounting plate coupled to the intermediate connection tab, and a ramp bracket assembled with the mounting plate and fixedly coupled to a vehicle body together with the mounting plate, in which the mounting plate and the ramp bracket are assembled as a coupling hook of the mounting plate passes through a hook hole of the ramp bracket.