This Thesis is to attempt ontological investigation to overcome the problems raised by the apperance of virtual reality due to the progress of information technology. Deconstruction and constructive ontology which have been used to interpret virtual reality have been criticized in view of realism. Mādhyamik-śāstra criticizes not only identity theory but also deconstruction and nihilism through the theory of ultimate truth and conventional truth. Therefore through the discussion of interdependence interpretation of causality and theory of ultimate and conventional truth, it is shown that Mādhyamika-śāstra can be alternative ontology for virtual reality. Because the virtual reality emerged by network and actual reality are interdependent, actual reality can learn its limit through virtual reality and virtual reality recognize that it should be based upon actual reality. So, it is claimed that the freedom of virtual reality should be pursued in the context of interdependence instead of being pursued independent of actual network. The multiple communinity created in virtual reality can have causal unity and overcome the problems of multiple personality and split personality. It is claimed that the virtual reality is the creative expansion of life world rather than the expansion of desire.