Objective To study the roles of uPA and TGF-β1 on the etiology of preeclampsia(PE).Methods The levels of uPA and TGF-β1 were determined in 30 patients with PE. The data were compared with those of normal pregnant group(n=12).The levels of uPA and TGF-β1 in placenta tissue extraction and plasma were measured by means of enzyme linked immunosorbent assay(ELISA).Results (1)The level of uPA in placenta in PE group (11.42±4.67) ng/g was lower than that in normal pregnant group[ (32.62±2.85) ng/g, P 0.05]. (2)The level of uPA in plasma in PE group (466.61±34.68) pg/ml was lower than that in normal pregnant group[ (649.47±41.12) pg/ml, P 0.05]. The level of TGF-β1 in plasma in PE group (13.30±4.57) ng/ml was higher than that in normal pregnant group[ (9.617±4.19) ng/ml, P <0.05]. The was no significantly statistical difference in the levels of TGF-β1 between the severe PE