Objective: To study the level of serum plasminogen activator inhibitor 1(PAI-1) and expression of PAI-1 mRNA in visceral and subcutaneous adipose tissues of C57BL/6 mice which were normal weight or obesity and the effect of rosiglitazone (RSG) treatment. Methods: Male C57BL/6 mice were divided into control group fed with chow diet, high-fat group fed with high fat diet and high fat+RSG group fed with high fat diet for 8 weeks and supplemented with rosiglitazone for other 4 weeks, randomly. 12 weeks later, serum total triglyceride, total cholesterol and PAI-1 level were detected and the expression of PAI-1 mRNA in adipose tissues was also measured. Results: The body weight of mice in high-fat + RSG group was significantly higher than that in high-fat group and control. RSG treatment could decrease serum total triglyceride. High-fat diet could increase serum PAI-1 level, but RSG treatment could decreasePAI-1 level of mice with high feeding. The expression of PAI-1 mRNA of epididymal adipose tissues in all groups was all significantly higher than subcutaneous adipose tissues. RSG treatment could decrease the expression of PAI-1 mRNA in subcutaneous adipose tissues, but no effect in epididymal adipose tissues. Conclusion: The level of serum PAI-1 and the expression of PAI-1 mRNA were different between visceral and subcutaneous adipose tissues in both normal and obese mice. RSG treatment contributed to improve blood fat, decreased the level of serum PAI-1 and the expression of PAI-1 mRNA in subcutaneous adipose tissues.