A pallet includes a main extension member and support members. The main extension member includes a rotary sleeve and two threaded bars, which are respectively inserted into the rotary sleeve through two ends of the rotary sleeve to be connected in a rotatable manner through threading engagement. The support members each include first and second support elements pivoted to each other. An end of each threaded bar that is distant from the rotary sleeve is pivotally connected to the pivotal connection between the first and second support elements. Rotation of the rotary sleeve allows for adjustment of a distance between the two threaded bars to change a bending condition therebetween so as to vary a size of the pallet. The variation of the size of the pallet is thus made flexible to suit the need for transportation of products of various sizes and thus saving costs of transportation and storage.