Open source seed is the extension of the open source movement in breeding areas. It aims to realize the free use of germplasm and technology in the process of plant production， breeding， reproduction and distribution， and to overcome the negative impact of exclusive intellectual property protection on breeding innovation. The idea of open source seed adheres to the concept of freedom， openness and sharing. It does not deny intellectual property rights， nor does it mean that it is free or has no restrictions and responsibilities. The prevention of the privatization of germplasm resources， the accumulation of breeding innovation， and the commonality of seeds and software are the main reasons why the open source movement extends to the breeding field. Open source seed has the practical value of integrating breeding resources， promoting breeding innovation and ensuring national food security. The practice of other countries shows that open source seed falls into three modes： moral commitment， open source license and farmer cooperation. With the emphasis on breeding innovation and breaking through “bottleneck” in key technologies of seed sources， China can try to implement open source license model in University and research institutions funded by financial funds， encourage other breeders and farmers to join in promoting breeding innovation and realize the sustainable development of the seed industry.