A seal includes a buckling portion. The buckling portion is composed of two H-shaped members that are flexibly connected. The two H-shaped members are buckled with each other to form a mounted state. The H-shaped member has a first arm and a second arm which are parallel to each other, and a connecting portion which connects the first arm and the second arm. The connecting portion has an arcuate surface. The arcuate surfaces of the two H-shaped members cooperatively define a hollow cavity when the two H-shaped members are in the mounted state. A vacuum assembly and a refrigerator are disclosed to respectively have the seal.