OBJECTIVE To determine the characteristics and regularity of fibronectin mRNA expression in diabetic ulcers, and to investigate the relationship between the changes of fibronectin mRNA expression and pathogenesis of diabetic ulcer. METHODS Biopsies were removed from the margins of diabetic foot ulcers, included surrounding skin as experimental group, and the biopsies from normal skin of the same patients as control group. The mRNA expression of fibronectin was measured by quantitative RT-PCR technique. RESULTS The mRNA expression of fibronectin could be detected in both normal skin and diabetic foot ulcers, but the level of expression in diabetic ulcers was lower than that of normal skin. CONCLUSION The level of mRNA expression of fibronectin in diabetic ulcers is decreased, which suggest that the down-regulation of transcription may be one of the mechanisms of chronic impaired ulcers.