This study was carried out to analyze the effect of direction of wind load and machinery house location on the stability of container crane loading/unloading a container on a vessel. The overturning moment of container crane under wind load at 50m/s velocity was estimated by analyzing reaction forces at each supporting point. And variations of reaction forces at each supporting point of a container crane were analyzed according to direction of wind load and machinery house location. The critical location of machinery house was also investigated to install a tie-down which has an anti-overturning function of container crane at the land side supporting point.