Sustainability or sustainable development as an objective or as a definitions is wirely used since the 1992 Rio Conference on Sustainable Development. There are many attempts to clarify the content of it, most of them covering inter- and intragenerational equity, integration, the different means and methods of long-term thinking. While it is still a controversial question, it is also difficult or even harder to specify the legal content of such a policy matter. The law of sustainable development shall be able to meet the challanges of clarity, enforceability, thus one should try to be more specific then it is acceptabel in the wider the political context. Several international documents, conventions, even EU legislation wants to come closer to the problem. If we wish to translate the content into the legal language, then there are some elements of such a legal system, which we would like to underline: inter-generational equity and right to environment, public participation, cooperation, integration, precaution and subsidiarity. There is also a newly emerging element of the legal understanding – imported from ecology –, which needs greater attention today, that is resilience.