There are two interesting differences in roll control response characteristics between an aircraft and a paraglider: 1) Opposite roll angle is generated by the same control surface deflection: and 2) to keep the roll angle constant, an aircraft requires a pilot to return the control wheel to the nearly neutral position, but a paraglider requires him to keep the control surface deflection. Although it is commonly accepted that the main factor producing these differences would be the adverse yaw characteristics, the essential mechanism has not yet been clearly determined. This study focuses on features in their airframe configurations, and aims to determine the physical mechanism which produces their differences in roll control responses. Results showed that not only adverse yaw characteristics but also lower center of gravity position and decrease of vertical fin area in a paraglider are the main parameters.