We surveyed Preah Pithu monument group site in Angkor. We made the map of present condition throughout the actual measurement and 3D scan. And we restored the floor plan, and completed the map of site placement. During this processing, we confirmed the middle axis of temples and studied the relation of temples and made clear the order of sites. Throughout this studying, we verified the middle axis of sites is not matched in Preah Pithu monument group. It is different aspect comparing with general Khmer religion architectures which were built with the planification belonging to strong royal authority and shared main axis through whole sites. In other words, we can estimate that Preah Pithu monument group was not built with planification rather than expanded as occasional demand during the process of actual use