The aim of this study was to analyze thedistribution of plasminogen activator inhibitor-1 (PAI-1)promoter 4G/5G polymorphism in healthy Chinese andcompare the transcription activity of the two PAI-1promoters using luciferase reporter vector pGL3. PAI-1promoter 4G/5G polymorphism was analyzed in 77healthy Chinese using allele-specific polymerase chainreaction (PCR). The PAI-1 promoters from individualshomozygous for the insertion (5G) and deletion (4G) werecloned into luciferase reporter vector pGL3, respectively.The transcription activities of the two promoters (PAI-1-4G and PAI-1-5G) were then compared using the luciferasereporter vectors expressed in ECV304 and HepG2 celllines. Among the 77 healthy Chinese the genotypefrequency for 4G/4G, 4G/5G, and 5G/5G was 49.1,44.1, and 6.5%, respectively. Both of the two PAI-1promoters cloned into luciferase reporter vector pGL3,expressed very well both in ECV304 and HepG2, and havesimilar basic transcription activity. Thrombin (10-20 U/ml) has no effects on the transcription activity of the twopromoters expressed in ECV304, while in the HepG2 cellline interleukin-1 (IL-1) 158 U/ml increased the transcriptionactivity of PAI-1-4G by 67% (p<0.05, n=5) withouteffects on PAI-1-5G transcription activity. The distributionof PAI-1 promoter 4G/5G polymorphism in Chinese isobviously different from that in Caucasians with the 4Gallele more frequently found in Chinese. PAI-1 promoter4G/5G polymorphism does not alter basic transcriptionactivity and 4G promoter has increased response to IL-1.