Immune abnormalities in psoriasis vulgaris are described. Anti-stratum corneum antibodies deposited with C3 have been found in patients with psoriasis. A lot of other immune abnormalities identified in psoriasis: increased serum IgG and IgA levels, lowered DNCB-sensitization, alteration in polymorphnuclear leukocytes (PMN) function, decreased number of T cells, lack of response to concanavalin A (ConA) and an increase in the polyclonal B cell activation. the authors believe that the immunoregulatory defect is due to the disorder of the skin.