A package of an environmental sensitive electronic element including a first substrate, a second substrate, an environmental sensitive electronic element, a flexible structure layer and a filler layer is provided. The environmental sensitive electronic element is disposed on the first substrate and located between the first substrate and the second substrate. The environmental sensitive electronic element includes an anode layer, a hole injecting layer, a hole transporting layer, an organic light emitting layer, a cathode layer and an electron injection layer. The flexible structure layer is disposed on the environmental sensitive electronic element and includes a soft layer, a trapping layer and a protective layer. The material of the trapping layer is the same as the material of the electron injection layer. The filler layer is disposed between the first substrate and the second substrate and encapsulates the environmental sensitive electronic element and the flexible structure layer.