Organisms into which heterologous DNA has been artifically introduced and stably integrated in their genomes are termed transgenic. Since 1985, a wide variety of transgenic fish species have been produced by microinjecting or electroporation into fertilized or unfertilized eggs. These transgenic fish can serve as excellent experimental models for basic scientific investigations as well as biotechnical applications. In this paper, using research results generated in our laboratories and those of others as examples, we will review the current status of the transgenic fish research and illustrate the potential application of this technology in both basic research and biotechnological applications.