A small-size trampoline includes a frame assembly to support a jumping bed at a required height. The frame assembly includes front and rear frames, two side frames, and front and rear transverse bars connected to and between the two side frames. The front and rear frames and the side frames are so shaped that they could be vertically connected together. Each of the front and rear frames and the side frames includes a horizontal main section of a predetermined length, on which two vertical leg sections are formed. When the front and rear frames and the side frames are vertically connected to one another at the leg sections, they together provide an overall height equal to the height required by the jumping bed, and therefore allow the fully disassembled trampoline to have a largely reduced volume for economical packing.