A curtain airbag device is provided that allows for smooth downward deployment of a curtain airbag. In one form, a C-pillar has a guide rod attached thereto for guiding a rear portion of a curtain airbag when the curtain airbag is being inflated downward. The rear portion of the curtain airbag has a link strap attached thereto. A front end of the link strap is provided with a loop which is loosely wound around the guide rod. For guiding downward movement of the link strap, a linear member extends between a lower portion of the curtain airbag and the link strap. The linear member extends through guide components. During a downward deployment process of the curtain airbag, the linear member pulls the loop of the link strap downward. Thus, the link strap moves downward smoothly along the guide rod for smooth deployment of the curtain airbag.