Transgenic fish research is in the direction of application, and the "all fish" growth hormone gene transfer fish is under conditional field trial. However, some problems remain to be solved such as uncontrollable behavior and unstable heredity oftransgene, etc. Nuclear transplantation is a major technique to solve these problems, so a study is conducted to know how to make homogenous transgenic fish by nuclear transplantion This paper includes five pats as follows. Part 1: It is a review abort achievements oftransgenic fish, nuclear transplantation and embryonic stem cell research in recent years. Part 2: Using a nuclear transplantation approach, the integration and expression of the green fluorescent protein (GFP) gene in the embryogenesis of transgenic loach (Misgurnus anguillicaudatus Cantor) was studied. The GFP gene expression was first observed at the gastmla stage, which is consistent with the initiation of cell differentiation of fish embryos. The time course of the foreign gene expression is correlated with the regulatory sequences. The expression efficiency also depends on the gene configuration: the expression of pre-integrating circular plasmid at early embryos is higher than that of the linear plasmid. The integration ofthe GFP gene was first detected at the blastula stage and lasted for quite a long period. When two types of different plasmid were co-injected into fertilized eggs, the behavior of their integration and expression was not identical. Part 3: Nuclear transplantation was carded through with transgenic fish embryos of Carassius auratus, Pengze var and Cyprimus carpio, Huanghe var at blastula and gastrula stage as donors. Foreign gene was detected by PCR in five nuclear transplanted fish of Carassius auratu. Pengze var and one nuclear transplanted fish of Cyprinus carpio. Huanghe var. There was not any homozygote of transgenic fish acquired The limitation was analyzed about acquiring homozygote of transgenic fish by nuclear transplantation using transgenic embryos at early stage as donors, and the future strategy was put forward. Part 4: Nuclear transplantation was carded out with somatic cells including kidney cells, tail fin cells and cultured tai fin cells of F_4 hGHgene tmnsfened red carp as donors, and unfertilized eggs of loach or Huanghe carp as recipients. The results show that hGH gene stablely exists in the F_4 red carp. The recombined embryos could develop, but no one develope to term. The hGHgene exists in all nuclear transplant embryos detected by PCR. The results suggested that nuclear transfer of somatic cells might acquire cloned transgenic fish. Part 5: The ccMTeGFP plasmid was used to transfect CAB cells fiom crucian cap blastula by lipofection method, and the GFP gene positive cells were acquired by G418 selection, the cell morphology and growth were not affected by GFP gene. The pCMVeGFP or pMhGHtransfected CAB ceU nuclei were transferred into silver carp unfertilized eggs, and nuclear transfer embryos with foreign gene were acquired. The developmental ratio of nuclear transfer embryos was higher from cells incubated at 4 ℃ for 24h than from fresh cells. It is suggested that homogenous transgenic fish may be acquired through nuclear transplantation using transfected cells, and the status of donor ceils significantly affect the efficiency of nuclear transplantation. It is proposed to make homogenous transgenic fish by tranfecting cultured cells, selecting transfected cells, transferring selected cell nuclei into oocytes, and culturing nuclear transfened fishes. However, There ate some problems still retrain such as transfecting and selecting cells earlier to keep the diploid, coordinating cell cycle stages of donors and recipients to increase nuclear transplant efficiency, etc.