An installation structure of a vehicle curtain airbag, which utilizes a holding member of a curtain airbag strap that disengageably holds a strap which connects an end portion of a curtain airbag main body to a pillar of a vehicle body, and that can be attached to the vehicle body while holding the strap, the holding member comprising: a slope oriented towards the exterior and the bottom of the vehicle body when attached to the vehicle body; wherein the strap can be held on a top face of the slope, with the curtain airbag main body in a stored state; and the slope allows guiding, towards the exterior of the vehicle body, the strap moving in response to deployment and inflation of the curtain airbag main body, the installation structure comprising: a vehicle body including a front pillar and a roof side rail connected to the front pillar; a front pillar garnish provided in the front pillar so as to cover the front pillar from inside the vehicle body, characterised in that said front pillar garnish has a first locking edge section disengageably locked to the front pillar; a roof garnish provided in the roof side rail so as to cover the roof side rail from inside the vehicle body, and having a second locking edge section which, in a form connected to the first locking edge section, is disengageably locked to the roof side rail; a curtain airbag main body, provided in a stored state between the roof garnish and the roof side rail, and being capable of deploying and inflating towards the bottorn of the vehicle body through disengagement of the second locking edge section from the roof side rail; and a strap that extends along the front pillar, between the front pillar and the front pillar garnish, from a front portion, in a vehicle body front-rear direction, of the curtain airbag main body in a stored state, the strap connecting the curtain airbag main body and the front pillar, wherein the strap is disengageably held by the holding member which can be attached to the vehicle body while being positioned at a position covered by at least one of the front pillar garnish and the roof garnish. a vehicle body including a front pillar and a roof side rail connected to the front pillar; a front pillar garnish provided in the front pillar so as to cover the front pillar from inside the vehicle body, characterised in that said front pillar garnish has a first locking edge section disengageably locked to the front pillar; a roof garnish provided in the roof side rail so as to cover the roof side rail from inside the vehicle body, and having a second locking edge section which, in a form connected to the first locking edge section, is disengageably locked to the roof side rail; a curtain airbag main body, provided in a stored state between the roof garnish and the roof side rail, and being capable of deploying and inflating towards the bottorn of the vehicle body through disengagement of the second locking edge section from the roof side rail; and a strap that extends along the front pillar, between the front pillar and the front pillar garnish, from a front portion, in a vehicle body front-rear direction, of the curtain airbag main body in a stored state, the strap connecting the curtain airbag main body and the front pillar, wherein the strap is disengageably held by the holding member which can be attached to the vehicle body while being positioned at a position covered by at least one of the front pillar garnish and the roof garnish.