To provide a side panel installing structure in a load-carrying platform by which the side panel can be installed to the side of the load-carrying platform simply, and furthermore, the apperance of the side of the load-carrying platform is not hurt more than necessary even when the side panel is not installed to the side of the load-carrying platform.

At the upper end of a side panel 4 to cover the outer side surface of a load-carrying platform 1, an installing piece 51 extending along the platform 1 is provided, and it is fixed on the upper surface on both sides of the platform 1 through a bolt 7 and a nut 72, while the lower end of the side panel 4 is fixed to the outer side surface at the lower end of a side wall 13 of the load-carrying platform 1 through a clip 8 to hold both lower ends.