As the environmental paradigm is the major issue today, the guideline of the ecological design in the interior architectural field is needed. One on the knowledge necessary to plan the ecological interior architecture as a designer is the spectification related factors for planning, which should be applied in materialistic matters. In this paper, the knowledge of materials and products needed to design interior space considering the ecological factors is studied. And, a guideline for the eco-design is investigated for the expression of the environmentally friendly perception.