Abstract: A gravity door hinge in which a cam is inserted non-rotatably into the lower half of a socket provided in a fixed member, the upper end of an axial rod is inserted non-rotatably into an axial bore hole provided in a rotational member, a cam follower is fitted rotatably around the middle of the axial rod by inserting the axial rod through a central hole bored in the cam follower, the lower half of the axial rod is inserted rotatably into an axial hole formed by hollowing out the center of the cam, the cam follower is fitted rotatably into the upper half of the socket, on top of the cam housed in the lower half of the socket so that an inclined cam surface formed on the lower end of the cam follower comes into close contact with an inclined cam surface formed on the upper end of the cam, and the base of the socket is completely closed.