A new type of semi-rigid thin-walled steel-concrete composite beam-to-column joint has been proposed in this paper.Five semi-rigid composite beam-to-column joint specimens subjected to hogging moments under monotonic loading were tested to study the static behavior of this new type of joint.The main variable parameters for the five joint specimens were the longitudinal reinforcement ratio and the joint type.The experimental results designated that the magnitude of extension of the longitudinal reinforcement is the most important factor that influenced the moment-rotation characteristic of the new type of joint.The concrete slabs could resist 3.8%-19.1% of the total shear load applied to the cross-sections near the beam-to-column connection.The edge stiffened elements,such as the flange of the lipped I-section thin-walled steel beam,were capable of having considerable inelastic deformation capacity although they had comparatively large width-to-thickness ratios.The shear failure of the concrete cantilever edge strip must be taken into account in practical design because it has significant influence on the anchorage of the longitudinal reinforcement in the new type of external joints. A new type of semi-rigid thin-walled steel-concrete composite beam-to-column joint has been proposed in this paper. Flexible semi-rigid composite beam-to-column joint specimens subjected to hogging moments under monotonic loading were tested to study the static behavior of this new type of joint. The main variable parameters for the five joint specimens were the longitudinal reinforcement ratio and the joint type. the experimental results designated that the magnitude of extension of the longitudinal reinforcement is the most important factor that influenced the moment-rotation characteristic of the new type of joint. The concrete slabs could resist 3.8% -19.1% of the total shear load applied to the cross-sections near the beam-to-column connection. The edge stiffened elements, such as the flange of the lipped I-section thin-walled steel beam, were capable of having considerable inelastic deformation capacity although they had comparatively large width-to-thickness ratios. The shear failure of the concrete cantilever edge strip must be taken into account in practical design because it has significant influence on the anchorage of the longitudinal reinforcement in the new type of external joints.