A rider characteristic determining apparatus configured to determine control characteristics of a rider controlling a saddle riding type vehicle in which a vehicle body can be leaned at the time of turning, comprising: a first vehicle state detector configured to detect at least one of a yaw rate and a yaw angle of the saddle riding type vehicle; a turning movement discriminating unit configured to discriminate a section where the saddle riding type vehicle has made a turning movement; a second vehicle state detector (33, 35) configured to detect at least one of a roll rate, a roll angle, a pitch rate, a pitch angle, and a caster angle of the saddle riding type vehicle; a component separating unit configured to separate detection values detected by the first vehicle state detector and the second vehicle state detector (33, 35) in the turning movement section discriminated by the turning movement discriminating unit, into adjustment components that are high-frequency band components higher than a threshold frequency set beforehand, and prediction components that are low-frequency band components lower than the threshold frequency; a vehicle stability characteristic determining unit configured to determine a vehicle stability characteristic of the saddle riding type vehicle; and a turning characteristic determining unit configured to determine a turning characteristic of the saddle riding type vehicle; wherein the vehicle stability characteristic determining unit includes a vehicle stability score calculating unit configured to calculate a vehicle stability score of the saddle riding type vehicle based on a ratio between the adjustment components and the prediction components separated from the detection value of the first vehicle state detector by the component separating unit; and the turning characteristic determining unit includes a turning performance score calculating unit configured to calculate a turning performance score of the saddle riding type vehicle based on the prediction components separated from the detection value of the second vehicle state detector (33, 35) by the component separating unit. a first vehicle state detector configured to detect at least one of a yaw rate and a yaw angle of the saddle riding type vehicle; a turning movement discriminating unit configured to discriminate a section where the saddle riding type vehicle has made a turning movement; a second vehicle state detector (33, 35) configured to detect at least one of a roll rate, a roll angle, a pitch rate, a pitch angle, and a caster angle of the saddle riding type vehicle; a component separating unit configured to separate detection values detected by the first vehicle state detector and the second vehicle state detector (33, 35) in the turning movement section discriminated by the turning movement discriminating unit, into adjustment components that are high-frequency band components higher than a threshold frequency set beforehand, and prediction components that are low-frequency band components lower than the threshold frequency; a vehicle stability characteristic determining unit configured to determine a vehicle stability characteristic of the saddle riding type vehicle; and a turning characteristic determining unit configured to determine a turning characteristic of the saddle riding type vehicle; wherein the vehicle stability characteristic determining unit includes a vehicle stability score calculating unit configured to calculate a vehicle stability score of the saddle riding type vehicle based on a ratio between the adjustment components and the prediction components separated from the detection value of the first vehicle state detector by the component separating unit; and the turning characteristic determining unit includes a turning performance score calculating unit configured to calculate a turning performance score of the saddle riding type vehicle based on the prediction components separated from the detection value of the second vehicle state detector (33, 35) by the component separating unit.