Objective：To investigate the expressions of interleukin-18（IL-18），interleukin 18 binding protein（IL-18BP） and inter－leukin 18 receptor（IL-18R） in eosinophil-enriched cells from patients with psoriasis，and the correlation among them. Methods： Blood samples from psoriasis patients and healthy controls（HC） were collected and incubated with the extracts of Artemisia pollen，dust mite，and Platanus pollen. Expressions of IL-18，IL-18BP and IL-18R in blood eosinophils were detected by flowcytometry. SPSS software was employed to analyze the correlation among them. Results：Levels of IL-18+ and IL-18R+ blood eosinophils in psoriasis patients were increased up to 3.7（Z=-3.070，P=0.002） and 4.1 folds（Z=-4.753，P=0.000），respectively. While IL-18 BP+ eosinophil was reduced by 87% compared with HC when cultured with medium only（Z=-4.556，P=0.000）. Dust mite extracts induced approximately 1.5-fold increase in IL-18+ eosinophils of psoriasis patients（Z=-3.548，P=0.000），and Platanus pollen extracts induced approximately 1.1-fold elevation in IL-18BP+ expression（Z=-3.445，P=0.000）. In addition，the proportions of IL-18BP+ and IL-18+ eosinophils in psoriasis patients were highly correlated（r=0.587，P=0.013）. Conclusion：Increased expressions of IL-18，IL-18R，and decreased expression of IL-18BP in eosinophil-enriched blood cells from psoriasis patients may suggest that IL-18，IL-18R and IL-18BP expressed in eosinophils may be involved in the pathogenesis of psoriasis. Anti-IL-18 agents or IL-18R blockers might become potential targets for psoriasis treatment.