This creation provides a kind of moon cup, including a container, system has an outer wall and an inner wall, the container extends to a closure bottom end from an open top end to form the cavity of a collection liquid, the inner wall has an annular inner fovea part apart from place from the open top end one, and the inner wall has an annular projection in place adjacent with the annular inner fovea part, and the container has flexible and elasticity； Wherein, which makes the open top end bend inwards by the combination of the annular inner fovea part and the annular projection to form a leakage-proof structure.本創作提供一種月亮杯，包括一容器，係具有一外壁及一內壁，該容器自一開口頂端延伸至一閉合底端以形成一收集液體之腔體，該內壁在自該開口頂端一距離之處具有一環形內凹部，而該內壁在與該環形內凹部相鄰之處具有一環形突起部，且該容器具有可撓性及彈性；其中，該容器藉由該環形內凹部與該環形突起部之結合而使該開口頂端向內彎折以形成一防漏結構。
