Disclosed is a network-on-chip system including an active memory processor for processing increased communication latency by multiple processors and memories. The network-on-chip system includes a plurality of processing elements that request to perform an active memory operation for a predetermined operation from a shared memory to reduce access latency of the shared memory, and an active memory processor connected to the processing elements through a network, storing codes for processing custom transaction in request to the active memory operation, performing an operation addresses or data stored in a shared cache memory or the shared memory based on the codes and transmitting the performed operation result to the processing elements.