Galloping is a kind of transverse aerodynamic instability phenomenon to which slender prismatic structures are prone under wind actions， and the mass damping parameter is a key factor in determining the galloping response. The present study aims to explore the influence of the mass damping parameter on the galloping of the H-shaped section with a small side ratio （width-to depth ratio as B/D=1.91）. By taking the H-shaped hanger of the Zengjiayan Jialing River Bridge as the prototype， this study inves?tigates the galloping response under the typical wind attack angles， based on the wind tunnel segmental model test of an H-shaped section with a side ratio B/D=1.91. The effect of the change of Scruton number caused by the mass and damping parameters is then examined on the galloping response under large wind attack angles. Finally， the feasibility of Scruton as a single parameter is discussed to describe the influence of mass damping parameter. The results demonstrate that the H-shaped section with a side ratio B/D=1.91 shows unsteady galloping with large amplitude at the attack angles of 0° and 70°， and compared with 0° attack angle，the change of galloping response at the attack angle of 70° is more sensitive as the Scruton number increases. The onset wind speed of the galloping is， at the attack angles of 0° and 70°， lower than that calculated by the classical quasi-steady theory， which is high and dangerous. Compared with 70° attack angle， the wind-induced vibration at 0° attack angle is more likely to occur due to its low?er onset wind speed， and has significant unsteady galloping. The mass ratio and damping ratio have different effects on the gallop?ing at different wind angles of attack. At the attack angle of 0°， the two can be uniformly represented by the Scruton number， but at a large attack angle of 70°， they cannot be accurately represented by the Scruton number. At last， some topics deserving further re?search are highlighted.