Abstract: A container seal, including a socket, a C-shaped ring, a pin, and a pointer, is provided. The socket has a jack, a slot, and a reservoir which connects to the slot. The C-shaped ring is disposed on the slot's slot wall. The pin has a tapered end and a trench disposed on a position having a first distance from an end surface of the tapered end. The tapered end passes through the C-shaped ring, making the C-shaped ring be snapped in the trench. The pointer has a neck portion and a head portion whose diameter is between the internal diameters of the slot and the reservoir. The head portion passes through the slot and enters into the reservoir, and the neck portion connects to the end surface. When the pin is pulled out, the pointer is separated from the end surface and dropped into the reservoir.