A vehicle floor structure characterized in that: the principal structure thereof is a double-deck structure comprising two panels formed from a thermoplastic fiber-reinforced composite material; within the region over which said double-deck structure extends, each panel has at least two contiguous reinforcing structures having convex open cross-sections; said reinforcing structures are provided with recesses in at least two locations; the reinforcing structures on one panel intersect those on the other panel; and the panels are joined together with the recesses provided in the reinforcing structures fitting into each other.
