According to the measuring and interviewed surveys of 56 Hue Traditional Garden Houses located in the Citadel area, the spatial organization of these houses have been transformed into various configurations. The transformation of Hue Traditional Garden Houses can be caused by either business venture, growth of family members, requirement of space for clan worship, flood prevention, public usage .and living purpose, or the combination of various causes. Besides, three directions of the transformations can be identified as well-horizontal plane, vertical plane and combined plane. With these three directions and the impacts of six causing factors, 9 variations of Traditional Garden Houses' transformation can be found. The transformation of Hue Traditional Garden Houses among the above 9 variations can also be observed. It is found that the transformation of nine variations can be classified into five directions. Each direction can be further divided into different types according to their possible transformation. Generally, Hue Traditional Garden Houses are transformed from simple to complex forms and spaces. These transformations mainly occur in nha phu (sub-house), while their nha chinh (main house) have not changed so much. This demonstrates that main house has an important role in the owners' spiritual life. Thus, the owners try to preserve and conserve main house for contemporary use.