Disclosed is a variable capacity type rotary compressor (1), in which a refrigerant sucked via one suction pipe (140) can be alternately sucked into each compression space via a communication passage between a plurality of cylinders (310, 410) to reduce the number of components and the number of assembly processes, thereby remarkably reducing fabrication costs. Refrigerant within an idling cylinder can be prevented from flowing back into another cylinder to improve the performance of compressor (1), a welding space can be ensured when connecting connection pipes to achieve welding automation and, thereby further reduce fabrication costs, and a mode switching valve (540) can be stably fixed to an appropriate position to attenuate noise due to vibration of the compressor.