To provide a rear seat installing device with a child seat anchor, capable of reducing work manhours and installation cost.

This rear seat installing device includes a bent panel-like base part 120 fixed to a floor panel 108 in the vicinity of a back face of a rear seat 102, the child seat anchor 122 of a predetermined shape arranged in a part formed in the base part by bending so as to correspond to a child seat installing child seat engaging member 114 extending to the vehicle rear from a child seat 110 and connected to the child seat engaging member, and a rear seat anchor 126 arranged in a part formed in the base part by bending and in a part corresponding to a rear seat installing rear seat striker 106 extending to the vehicle rear from the rear seat and fixing the rear seat striker.