Abstract: The shoring includes a pair of fixed frames opposed to each other and a pair of collapsible reinforcing frames disposed between both ends of the fixed frames, the reinforcing frames each having collapsible baluster struts whose base ends are pivotally connected between end portions of the fixed frames, a support rod whose base end is pivotally connected to an intermediate position of the baluster struts, and plural braces whose base ends are pivotally connected to end portions of the fixed frames and whose front ends are mounted vertically slidably to the support rod.