Sea perch embryonic stem cells (LJES1) are undifferentiated cell lines derived from midblastula of sea perch (Lateolabrax japonicus), and retained luripotency in vitro, which provide a unique tool for introducing random or targeted genetic alterations. For improving the transformation efficiency of exogenous gene into LJES1 cells, a simple and effective method of gene ransfer was established with several lipsomes transfection reagents. pCMVEGFP plasmids were transformed by three lipsomes reagents (genejammer, genejuice and metafectene) into LJES1 cells. Expression of green fluorescent protein(GFP) in the cells was detected by fluorescence microscope equipped with mercury burner. For evaluating transformation efficiency, cells expressing GFP in 12well plates were counted under fluorescent microscope. ransformation efficiencies of three lipsomesmediated LJES1 cells were compared, and effects of various factors were examined, such as incubation time of cells, initial incubation density, the doses of DNA and lipsomes, and ratio of DNA and lipsomes, etc. It was demonstrated that the highest transformation efficiency was acquired by genejammermediated GFP into LJES1, which was suitable for transformation of this cell line. For the same kind of lipsome, the ratio of DNA and lipsome for transformation of LJES1 is very important. It was found that 3 μL genejammer and 0.5 μg DNA gave rise to the optimal transfor mation efficiency of 27.3% for cells in 12 well plates with a ration of DNA and genejammer of 1∶6; 4 μL genejuice and 1 μg DNA gave rise to the optimal transformation efficiency of 12.1% with a ration of DNA and genejuice of 1∶4; and 6 μL metafectene and 2 μg DNA gave rise to the optimal transformation efficiency of 5.3% with a ration of DNA and genejuice of 1∶3. The efficiency of transformation increases slightly as the increase of the DNA and lipsomes amount, but decreases after reaching a definite amount. Otherwise, initial incubation density and incubation time of cells affected the efficiency of transformation. 20×104·mL-1 cells in 12 well plates are optimum, which should be 70%-90% confluence. The higher efficiency of transformation arrived in 12 and 30 h after incubation, and cells should be rapid growth. ES cellmediated gene transfer technique will be the most promising approach for producing sitemutated transgenic fishes with enhanced growth rate or disease resistance and in analyzing functions of fish genes. Optimization of onditions for lipsomemediated gene transfer with high efficiency would provide a technical foundation for genetic modifications in vitro.