Abstract: Objective To investigate the expression of dual oxidase 2 (DUOX2) in psoriasis vulgaris lesions, atopic dermatitis (AD) lesions and normal skin and its role in cutaneous anti-inflammation. Methods Tissue samples were harvested from psoriasis lesion area, psoriasis non-lesion area, AD lesion area and AD non-lesion area, as well as normal skin, the expression level of DUOX2 protein was detected by immunohistochemical staining. The mRNA level of DUOX2 was detected by reverse transcription polymerase chain reaction (RT-PCR) analysis. Results The expression of DUOX2 protein was observed in all groups which mainly located in basal layer, spinous layer and dermal papilla layer. Compared with the psoriasis non-lesion group and normal skin group, the expression level of DUOX2 protein in psoriasis lesion group was significant higher (P<0.01). The expression of DUOX2 protein in AD lesion group was stronger than that in AD non-lesion group and normal skin group (P<0.01). In addition, the expression level of DUOX2 protein in AD lesion group was significant higher than that in psoriasis lesion group (P<0.01). RT-PCR test revealed DUOX2 mRNA was expressed positively in psoriasis and AD lesions. Conclusion The strong expression of DUOX2 in psoriasis vulgaris lesion and AD lesion suggested that DUOX2 may play an important role in the mechanisms of cutaneous anti-inflammation.