An air-conditioning system in vehicle is installed in a vehicle in which a vehicle body center position and an aisle center position are different, and has an air conditioner. The air-conditioning system in vehicle has first and second outlets arranged on both sides of the vehicle in a vehicle width direction and discharging conditioned air having substantially the same air volume into an interior, and an air regulating member setting a merging position of air flows discharged from the first and second outlets to the position where the line segment connecting the vehicle body center position and the aisle center position is internally divided at a ratio of between 20:80 and 86:14.