In China there are many mixed driving roads which cause a lot of safety problems between vehicles and pedalcyclists. Research on driver behavior under risk scenarios with pedalcyclist is relatively few. In this paper driver brake parameters under naturalistic driving are studied and pedalcyclists include bicyclist, tricyclist, electric bicyclist and motorcyclist. Brake reaction time and maximum brake jerk are used to evaluate driver brake reaction speed. Average deceleration is used to evaluate the effect of driver brake operation. Maximum deceleration is used to evaluate driver braking ability. Driver behaviors collected in China are classified and risk scenarios with pedalcyclist are obtained. Driver brake parameters are extracted and statistical characteristics of driver brake parameters are obtained. Influence factors are analyzed with univariate ANOVA and regression analysis. The results show that driver brake parameters under risk scenarios with pedalcyclist obey a lognormal probability distribution. Driver brake reaction time when driver drives at intersections is significantly longer. Steering or not doesn’t significantly influence driver brake reaction time at intersection. The velocity at the time when a collision threat appears has no obvious relationship with brake reaction time. The type of pedalcyclist doesn’t significantly influence driver brake reaction time. Drivers brake faster in good lighting conditions. When vehicle goes straight and driver is faced with lateral incident, average braking deceleration is significantly bigger. This paper is important for research of driver behavior and development of advanced driver assistance system suited to road traffic in China.