Floor panel structure of vehicle body

A floor panel structure of a vehicle body, in which a floor of an automotive vehicle is formed by a floor panel coupled to a plurality of frame members which extend in substantially longitudinal and width directions of the vehicle, comprising:

• a panel area provided at said floor panel, said panel area being formed by being enclosed at least by said frame members,
• a heavy-weight area formed within said panel area, said heavy-weight area comprising an application-type of damping material which is provided at the substantially central portion of said panel area, and an asphalt-based damping material is provided at a peripheral area formed within said panel area, having a lower hardness and a greater specific gravity than that of said application-type of damping material provided at said heavy-weight area, the heavy-weight area being located at a substantially central portion of said panel area, and the peripheral area being located substantially around said heavy-weight area,
• wherein said heavy-weight area is configured so as to be heavier than said peripheral area.