【摘要】：正 Objective: To investigate the expression level of constitutive cyclooxygenase (COX-1) and inducible cyclooxygenase (COX-2) expression in progressive psoriasis and their significance. Methods: Applying reverse transcription-polymerase reaction (RT-PCR) technique to semi-quantitatively analyze COX-1 and COX-2 mRNA expression in the Peripheral Blood Monouclear Cells (PBMC) from 30 psoriatic patients and 30 cases of healthy subjects, and the correlation between COX and PASI (psoriatic area and severity index) was valu-ated. Results: Compared with normal controls, there was statistical differences in the COX-2 mRNA expression level of patients (p0.01), but no that of COX-1 (p0.05). There was positive correlation between COX2 and PSAI (r=0.683,p0.01). However, such a positive correlation was not shown between COX1 and PSAI. Conslusion: The higher level COX-2 expression can stimulate over-production of PGs and may be involved in the pathogenesis of progressive psoriasis.