The　inexplicit　efficiency　of　environmental　property　rights　lies　in　its　fuzziness.　Based　on　the　character　of　environmental　property　rights　discussed,　unit　environment　shows　intra　relationship　between　efficiency　and　duty　of　environmental　property　rights,　and　constructs　a　symmetrical　system　arrangement.　Through　analyzing　the　possibility　and　feasibility　of　unit　environmental　property　rights,　the　significance　of　symmetrical　system　arrangement　to　avoid　the　inexplicit　efficiency　of　environmental　property　rights　is　discussed　in　this　dissertation　from　the　aspect　of　the　validity　of　offering　and　implementing　system.　Copyright　©　2007,　Chinese　Society　for　Sustainable　Development　and　Research　Center　for　Sustainable　Development　of　Shandong　Province.　Electronic　version　published　by　Elsevier　Limited.　All　rights　reserved.