At container terminals, a major measurement of productivity can be work-efficiency in quay-side. At an apron, containers are loaded onto the ship and unloaded to the apron by quay-crane. For improving the productivity of quay cranes, the more efficient Y/T operation method is necessary in container terminals. Between quay-side and yard area, current transferring method is single-cycling which doesn't start loading unless it finishes unloading. Dual-cycling is a technique that can be used to improve the productivity of quay-side and utility of yard tractor by ship loading and unloading simultaneously. Using the dual-cycling at terminals only necessitates an operational change without purchasing extra equipment. Exactly, Y/T operation method has to be changed the dedicate system to pooling system. This paper presents an method of efficient ship loading and unloading plan in container terminals which use the dual-cycling. We propose genetic and tabu search algorithm for this problem.