Observation Obstacle is an artwork produced by SHI Qing during his programme entitled Plant Republic 2. It is a series composed of four pieces all bearing the appearance of both architectural structure and natural landscape. Between its running configuration and complicated system of "wildness" that is Plant Republic, there lies probably certain connections. Both control and loss of control during implementation constitute his production. By discussing "the possibility of validity of artwork", SHI offers his own answers to the question "under which condition does an individual become an ecological system?": the existence of power model of community in a paralleled system, coupled by his description of the community "which rests on external organisation rather than internal integration where multiple individuals co-exist constantly at distance".