The purpose of this study is to analyse the interrelationship between the international legal protection of modern biotechology and sustainable agricultural development. Recently advanced biotechnological innovations and its resulting GMOs urge us to rethink the meaning and scope of sustainable agricultural development in the novel contexts of this biotechnological millennium. In particular, when considering both probable promises and perils resulting from biotechnological applications, intellectual property protection of agro-biotechnology should take into more careful account the social impacts as well as the economic values of it. The existing international legal regimes for intellectual property protection, however, seem to be somewhat inappropriate to secure sustainable agricultural development. Therefore, I hope that future negotiations for rebuilding international legal systems for intellectual property protection of agro-biotechnology will be more favourable to the environment, biodiversity, equity, and sustainable development of agriculture.