In this paper, we propose an open 3D shared space construction scheme based on the concept of Symbiotic Computing which we have been promoting. Existing 3D collaborative work supporting systems have some limitations with their 3D shared space construction and inter-application cooperation because these systems are basically closed nature. To break these limitations, we are developing symbiotic collaborative work supporting system which can effectively support remote collaborative work. Our scheme enables us to easily and flexibly build collaborative work environment by reusing and combining space definitions and applications designed by the general public such as WWW environment. In addition, we describe design and implementation of a prototype system, and confirm feasibility of our proposed scheme through experiments by using the prototype system.