Fixed part for floor and floor using same

The invention relates to a fixed part for a floor and the floor using the same. The fixed part for the floor comprises a base part, two arm parts and two tongue parts, wherein the base part is provided with a punched hole used for being penetrated by a nail to fix the fixed part on a support beam; the two arm parts extend upwards from the same side edge of the base part; and the two tongue parts respectively and horizontally extend from one of the arm parts towards opposite directions and respectively support against a male plate body and a female plate body, thus a deformation amount generated due to temperature variation can be tolerated between the male plate body and the female plate body through the elastic deformation supplied by the fixed part disclosed by the invention.