A slidable constructing plate comprises a protrusion and a notch on its peripheral surfaces. The protrusion is corresponding in shape to the notch. Furthermore, one groove is recessed between the top surface of the plate and the protrusion. Another groove is recessed between the bottom surface of the plate and the protrusion. One rib protrudes between the top surface and the notch, and another rib protrudes between the bottom surface and the notch. The grooves are corresponding in shape to the ribs. Two adjacent slidable constructing plates can be connected and fixed by mutual sliding through the protrusion sliding into the notch and the ribs sliding into the grooves. Slidable structures are provided to connect two adjacent slidable constructing plates to easily and firmly construct diversified products such as floors, ceilings, cabinets, and drywalls.