Abstract: A lamp shade assembly includes a foldable shade having an upper edge and a lower edge to define an inner cavity therebetween, a top frame mounted at the upper edge of the foldable shade, a bottom frame mounted at the lower edge of the foldable shade, and a supporting frame detachably mounted between the top frame and the bottom frame within the inner cavity of the foldable shade for applying a stretching force on the foldable shade. The stretching force of the supporting frame is greater than a weight of the foldable shade, so that the foldable shade is stretched to provide a tension surface extending between the upper edge and the lower edge thereof, so as to form a collapsible lamp shade which is facilitated to be disassembled into a compact unit for storage and carriage and quickly assembled to tensely support a foldable shade.