A rail-type grounding terminal structure composed of a metal grounding member and an insulating housing. The grounding member has better operation elasticity and can be easily tightly connected with a grounding rail. The grounding member includes a metal insertion leg mountable on a leaf spring mount, a bow section connected with the metal insertion leg and a first end and a second end respectively outward extending from the bow section and latched on a grounding rail. The metal insertion leg has a slightly outward deflected head end and a neck wall formed thereunder. When the metal insertion leg is mounted on the leaf spring mount, the leaf spring mount exerts a reaction force to urge the grounding member to tightly attach to lower side of the housing. Therefore, a gap is defined between the grounding member and the housing for a serviceman to separate the grounding member from the rail or connect the grounding member with the rail.