Abstract: The essential derived variety (EDV) system is helpful to prevent modified breeding and encourage original innovation. However, this system has not been introduced into the legal protection system of variety rights in China. Therefore, the present assay systematically analyzed the origin, implementation difficulties and countermeasures of EDV system. The EDV system stems from the restriction of breeding exemption. As far as factual effects are concerned, the EDV system does not affect others to use original varieties for breeding. In terms of legal effects, the EDV system has certain restriction on breeding exemption, so the commercial use must be authorized by the original variety owner. The implementation of the EDV system may face difficulties in judging essential, obstacles to the commercialization of derived varieties and increasing the burden on farmers. Based on the consideration of professional technology, the judgment standard of threshold should be determined by the department of variety authorization. The court should apply the judgment standard in the dispute of variety infringement, to appropriately judge “essential” by means of the technical investigation officer system. Liability rules should be introduced to remove the obstacles in commercialization of derived varieties. And state subsidies should be adopted to alleviate the cost burden that the EDV system may impose on farmers. If the EDV system were introduced into China, the relevant supporting systems should be well designed.

Key words: essential derived variety, breeding exemption, essential, liability rules