VEHICLE LOWER-PART STRUCTURE

Provided is a vehicle lower-part structure including a pair of center side members arranged under a floor of a vehicle; a first cross member and a second cross member connecting the pair of center side members; a main battery arranged in an underfloor space; one or more support plates arranged at a corner of the underfloor space; and a water tank placed on the support plate, in which the support plate is connected to both the center side member and the first or second cross member and connects the two.