Abstract: Objective 　To establish stable expression cell line transfected with eukaryotic expression vector of PTEN. Methods 　To clone the wild-type PTEN gene, total RNA was isolated from human placenta tissues. A cDNA of human PTEN was obtained by optimized RT-PCR and sequenced, and then the cDNA f ragment was put into the eukaryotic expression plasmid pcDNA 3. 1 ( + ) to const ruct pcDNA 3. 1-PTEN. Cells of esophageal squamous cell cancer cell line EC9706 were t ransferred with pcDNA 3. 1-PTEN using lipofectamine. The stable expression cells were screened by G-418. RT-PCR and growth curve were done for identifying the screened cells. Results 　The cDNA f ragment produced by RT-PCR had 100 % homology with wild-type PTEN gene sequence on GenBank by BLAST. The mRNA level of PTEN increased notably in the cell line we screened, and the growth of the cell line was very solely compared with control cell lines. Conclusion 　Because of cells of esophageal squamous cell cancer which stably express PTEN were successfully screened, it is concluded that a PTEN eukaryotic vector for stable expression in esophageal squamous cell cancer cell line has been constructed.