A lampshade includes a main body made of silicone rubber and preset in shape. The main body has its upper and lower circumferential edge respectively wrapped inside with an elastic bar and the inner side of its upper circumferential edge provided with a plurality of lugs respectively bored with an insert hole. The supporting bars at the upper end of a lamp holder are respectively inserted and fixed in the insert holes at the upper inner side of the main body to prop open the upper side of the main body and let the lower side drop downward naturally to form a lampshade for use. The lampshade made of flexible silicone rubber with excellent plasticity can be collapsed to diminish its dimensions when it is not in use.