A simple and efficient method for the purification of recombinant tissue-type plasminogen activitor(rt-PA) from a genetically manipulated CHO cell line(SGG) has been developed. The conditioned medium containing about 1500 U/ml of rt-PA from cultures of SGG cell in DMEM∶F12(1∶1) supplemented with 1% NBS was purified by a combination of absorbtion chromatography on MPG and affinity chromatography on Lysine-Sepharose 4B.The final product has a specific activity of 390 000 U/mg protein. The overall activity recovery was about 140% with 380 fold increase in specific activity. Analysis by SDS-PAGE in the presence of a reducing agent followed by silver staining showed one band with mass of molecular about 65 000 and two bands of 33 000～35 000. Reverse fibrin autography and Western blotting analysis showed that the product has natural t-PA characterization.