Air conditioning system for vehicles

An air conditioning system for vehicles comprising a refrigeration cycle having a variable displacement compressor, a condenser, an expansion mechanism and an evaporator, an evaporator temperature detecting means, an acceleration detecting means, and an evaporator temperature control means for controlling so as to coincide a value detected by the evaporator temperature detecting means with a target evaporator temperature by controlling a displacement control signal outputted to the compressor, characterized in that the air conditioning system has an air conditioning control means for changing the target evaporator temperature in the evaporator temperature control means to a target evaporator temperature at acceleration time which is a value of not lower than a target evaporator temperature having been set before acceleration, when the acceleration detecting means detects an acceleration condition of the vehicle. When the vehicle is accelerated, the displacement of the compressor is appropriately reduced, the acceleration performance can be improved, and a comfortable feeling can be maintained by suppressing an excessive elevation of the temperature of air blown into a vehicle interior.