A variable displacement wobble plate type compressor with a variable angle non-rotary wobble plate, having a suction chamber for refrigerant before compression, a discharge chamber for a compressed refrigerant, suction and compression cylinder bores, pistons reciprocated by the wobble plate within the cylinder bores for compressing the refrigerant, a crankcase with a chamber to receive therein a drive, and a wobble plate mechanism mounted about a drive shaft connectable to a rotary drive source, i.e., a vehicle engine, connected to the pistons to cause reciprocating motion of the pistons and capable of changing the wobble angle thereof, a first communication passageway providing a fluid communication between the crankcase chamber and the discharge chamber, a first control valve for closing and opening the first passageway in response to a change in a suction pressure of the refrigerant, a second communication passageway for permitting evacuation of a blowby gas from the crankcase chamber to the suction chamber, and a second control valve changing an extent of opening of the second communication passageway in response to a change in a fluid pressure within the discharge chamber with respect to a predetermined pressure level.