To provide a shade guide structure which can be used for an application in which the guide rails are curved, in which the sliding resistance is low, and which can reduce abrasion, a shade guide structure includes: a shade sheet wound around a winding shaft so that the shade sheet can be wound up and drawn out; guide belts provided along either side edge of the shade sheet and each joined to the shade sheet via a fixation part provided substantially at a center in a width direction; and left and right guide rails which guide the guide belts in a longitudinal direction when the shade sheet is wound up or drawn out, wherein each guide rail includes: a guide wall having a lock surface which is inclined relative to the shade sheet in a transverse cross section and locks the guide belts; a slot which is formed in the guide wall and through which the shade sheet passes; and a guide part which contacts the shade sheet such that the shade sheet extends from the fixation part substantially at a right angle to the guide belt.