To provide a wheel barrow with a retreatable auxiliary wheel properly usable as a wheel barrow, a two-wheel barrow or a three-wheel barrow by a worker depending on the intended use by detachably installing the auxiliary wheel to a conventional wheel barrow.

In the wheel barrow, a wheel barrow with a retreatable auxiliary wheel has a pair of bearings installed to both ends of a cross-linking frame for constituting a truck frame, an auxiliary wheel installing shaft rotatably journaled by the pair of bearings, an auxiliary wheel having one wheel or two wheels installed on the auxiliary wheel installing shaft, an auxiliary wheel automatic fixing-releasing lever arranged in the grip vicinity of a handle for grounding or separating the auxiliary wheel on or from the ground surface, and an auxiliary wheel automatic fixing device fixable to one bearing in any of a position where the auxiliary wheel becomes a grounding state and a position where the auxiliary wheel becomes a separated state by the auxiliary wheel automatic fixing-releasing lever.