This review introduces the development and applications of germ cell transplantation (GTC) (also called as surrogate production) as a newly emerging biotechnology. It is achieved by inducing germ-line chimerism between different species. Primordial germ cells (PGCs) and spermatogonial (or oogonia) are the key material of this technique. During the last decade, several different approaches have been developed for germ cell transplantation in fish, using different type of germ cell and recipients of various ages and life stages, such as blastula-stage embryos, newly hatched larvae and sexually mature specimens. All of these achievements give it advantages for application in many aquaculture research fields. (1) It has opened up new scenarios for the study of germ cell and niche biology and the possibility of generating transgenic fish. (2) Combined with the technique of cryopreservation of germ cell, whole testes and even whole fish, it could be a powerful tool for preserving valuable fish strains with desirable genetic traits and endangered species. (3) It presents a unique sex-selective breeding system that is superior to traditional endocrine sex control strategies. (4) It could serve as a novel and efficient method of producing fish seeds with increased genetic diversity for use in stock enhancement.