Abstract: A portable stamp assembly includes a cover composed of an upper cover and a lower cover pivotally connected to the upper cover. An ink receptacle is securely received in the lower cover and a plate having a pattern formed on a side thereof is pivotally connected to the upper cover. When the plate is at the first position, the plate is received in the first receiving space of the upper cover to have the pattern in constant engagement with ink inside the ink receptacle. When the plate is at the second position, the plate is connected to the lower cover so as to allow the upper cover, the lower cover and the plate to form a triangle.