Abstract： Objective To determine the serum level of chernokine CCL27 in patients with psoriasis vulgaris,and to analyse its clinical relevance.Methods A total of 61 patients(40 in progressive stage and 21 in stable stage)with psoriasis vulgaris,with an average disease duration of 37.97±14.34 years,were included in this study.Appropriate thempy was given to these patients.Serum samples were collected from the patients before and after therapy,as well as from 45 healthy human controls.ELISA was applied to examine the serum concentration of CCL27.Clinical severity of psoriasis vulgaris was assessed by psoriasis area and severity index(PASI)score.Results Serum level of CCL27 was 670.02±262.15 ng/L in psoriatic patients,compared to 373.10±92.84 ng/L in the controls(t=8.18.P＜0.01).Increased serum level of CCL27 was observed in patients with progressive psoriasis vulgaris compared to those with stable psoriasis (799.94±214.54 ng/L vs 422.57±135.53 ng/L,t=8.39,P＜0.01).After 8 weeks of therapy,a significant decrease was noticed in the serum level of CCL27 in patients who experienced≥70%reduction in PASI score(t=9.95,P＜0.01).but not in those experiencing a PASI reduction of＜70%(t=1.84,P＞0.05).The serum level of CCL27 was positively correlated with PASI score(r=0.58,P＜0.01).Conclusions The serum level of CCL27 is significantly elevated in patients with psoriasis vulgaris,and it is correlated with the disease severity.