A floating quay container terminal is used for loading or unloading from container ships from both sides of a floating quay. The side-by-side Liquefied Natural Gas (LNG) offloading operation from floating terminals to LNG carriers is very similar to that from super-container ships to floating quay-walls. The hydrodynamic interaction effects among a fixed quay, container ship and floating quay, which are parallel to one another, are investigated. The three body side-by-side arrangement is compared with the individual freely floating body in the absence/presence of the fixed quay to identify the interaction effects. Hydrodynamic coefficients of the interacting bodies are obtained using a three dimensional constant panel method, WAMIT. Using a vessel-lines coupled dynamic analysis computer program WINPOST, the relative motion between floating quay and container ship is simulated in time domain. It is assumed in the present study that the floating quay is positioned by a dolphin mooring system. This analysis provides the relative motion among container ship, fixed and floating quay to ascertain that container loading and offloading can be performed in the severe wave condition without any problem.