A pool apparatus comprising: a side wall having an outer side wall, an inner side wall and a plurality of structure drawstrings, the two sides of each of the structure drawstrings drawing respectively the outer side wall and the inner side wall, so as to maintain the pool apparatus to keep a predetermined shape, and the structure drawstrings comprising a main drawstring portion and at least two branch drawstring portions, and the main drawstring portion has a first main drawstring side configured to connect a first branch drawstring side of each of the at least two branch drawstrings, and a second branch drawstring side of each of the at least two branch drawstrings connecting respectively to different positions of the outer side wall or the inner side wall; a top sheet constituting a surrounding close shape, and the top sheet connecting the outer side wall along the outer periphery of the surrounding close shape, and the top sheet connecting the inner side wall along the inner periphery of the surrounding close shape; a bottom surface connecting to the side wall, such that after the inflation of the side wall, the bottom surface and the side wall constitute a space for carrying liquids; characterised in that the pool apparatus further comprises a plurality of ordinary drawstrings, each of the ordinary drawstrings including two sides connecting respectively to the inner side wall and the outer side wall, said ordinary drawstrings being configured at straight line portions of the predetermined shape; wherein the predetermined shape includes one or more turning portions; and wherein the plurality of structure drawstrings are disposed along the one or more turning portions. a side wall having an outer side wall, an inner side wall and a plurality of structure drawstrings, the two sides of each of the structure drawstrings drawing respectively the outer side wall and the inner side wall, so as to maintain the pool apparatus to keep a predetermined shape, and the structure drawstrings comprising a main drawstring portion and at least two branch drawstring portions, and the main drawstring portion has a first main drawstring side configured to connect a first branch drawstring side of each of the at least two branch drawstrings, and a second branch drawstring side of each of the at least two branch drawstrings connecting respectively to different positions of the outer side wall or the inner side wall; a top sheet constituting a surrounding close shape, and the top sheet connecting the outer side wall along the outer periphery of the surrounding close shape, and the top sheet connecting the inner side wall along the inner periphery of the surrounding close shape; a bottom surface connecting to the side wall, such that after the inflation of the side wall, the bottom surface and the side wall constitute a space for carrying liquids; characterised in that the pool apparatus further comprises a plurality of ordinary drawstrings, each of the ordinary drawstrings including two sides connecting respectively to the inner side wall and the outer side wall, said ordinary drawstrings being configured at straight line portions of the predetermined shape; wherein the predetermined shape includes one or more turning portions; and wherein the plurality of structure drawstrings are disposed along the one or more turning portions.