A trim cover fixing structure used in a vehicle seat 1 comprising a cushion body 16 having elasticity and a trim cover 17 covering the cushion body 16. This structure comprises engagement members 19a, 19b and 19c anchored near the edge of the trim cover 17, and an fixing member 23 provided with an engaging member (periphery 32) that engages with the engagement members 19a, 19b and 19c existing on the trim cover 17 in a state covering the cushion body 16. The fixing member 23 can apply tension to the trim cover 17 covering the cushion body 16 by engaging with the engagement members 19a, 19b and 19c, and in this state with tension applied, the trim cover 17 is anchored to the surface of the cushion body 16. This trim cover fixing structure has a simple structure and low cost and can apply desirable tension to the trim cover, and furthermore is easily applied to a vehicle seat having a split rear seat structure.