A protective element has a body, an inner connection layer, an outer connection layer, a heating layer and a low-melting-point alloy layer. The body is made of a single insulation material. The inner and outer connection layers are formed on two upper and lower surfaces of the body. The low-melting-point alloy layer is formed on the upper surface of the body and is electrically connected to the inner connection layer. The heating layer is mounted inside the body and is electrically connected to the low-melting-point alloy layer by the inner connection layer. The outer connection layer is electrically connected to the low-melting-point alloy layer and the heating layer. The outer connection layer is soldered on a power circuit. When the power circuit encounters overcurrent, the heating layer is heated to fuse the low-melting-point alloy layer faster. Thus, power circuit is cut to protect the power circuit.