The invention relates to a glass guide rail structure for an automobile rear door. The guide rail structure is characterized by comprising a uniform section part (1), a variable section part (2) and a buckle (3); the uniform section part (1) is formed in an extrusion manner, and the variable section part (2) is formed in an injection manner; during injection molding, the uniform section part (1) is placed in a mold for joint injection molding, and therefore the uniform section part (1) and the variable section part (2) are combined; and the glass guide rail structure is fixed to an automobile door metal plate through the buckle (3). The uniform section part (1) is formed by dense rubber and a metal framework (13) in a composite extrusion manner. The variable section part (2) is formed by dense rubber and a metal insert (24) in a secondary injection molding manner.