The present invention provides the structure of a bogie for a vehicle in a track type transportation system in which the vehicle runs along a predetermined track, which can be simplified, and lightweight and which can be run at a high speed with the maintainability therefor being enhanced, comprising a guide rail 14 laid on the track 12, guide wheels 51 capable of traveling being made into contact with the guide rail 14, a guide arm 48 attached thereto with the guide wheels 51, and a guide wheel support bracket 52 for supporting the guide arm 48 arranged underneath an axle 22 of the vehicle so that the guide arm 48 is pivotable around a pivotal vertical support shat 56, left and right of the vehicle, and the guide arm 48, the guide wheels 51 and the guide wheel support bracket 52 constitute a unit structure which is attached to the axle 22 or a bogie frame 26 of the vehicle.