Comparison studies of recombinant prourokinase(pro-UK) in various host cells, and expression vectors were carried out. Expression levels of vectors constructed in this study in different cell lines were compared. Mammalian cells expressing pro-UK were established. The levels of pro-UK expression in recombinant Namalwa, Vero and Sp2/0 cells are 200, 12.5 and 50 IU/(10(6) cells 24 h). pro-UK purities separated by immunoaffinity chromatograph are above 90%. Immunoabsorbent assay showed the ratio of pro-UK in CHO cells is lower than that from Vero and Namalwa cells. This study provide new host cells for pro-UK production.