Background : The recent experimental observations suggested that location of M. leprae in the Schwann cells was mediated by epineurial and endoneurial endothelial cells, giving M. leprae access to the inner compartment of nerves and thus to Schwann cells. CD1 is a family of nonpolymorphic β_2-microglobulin-associated transmembrane glycoproreins that is structurally related to classical MHC Ag-presenting molecules. but is encoded by a separate genetic locus. Recent report have described that human T cells specifically recognize foreign lipid and glycolipid antigens presented by CD1 proteins. Thus, it appeared likely that CD1 represents the key component of a MHC-independent pathway for antigen presentation to T cells. Objective : we observed expression of antigen presenting molecules, such as MHC class Ⅰ. Ⅱ and CD1. in the vascular endothelial cells and inflammatory cells of leprosy skin lesion. Methods : MHC class Ⅰ, Ⅱ and CD1 expression were studied using immunohistochemical stains. Results : 1. In immunohistochemical stain of HLA-A, B. C, the level of expression in vascular endothelial cells of the borderline tuberculoid leprosy is higher than that of borderline lepromatous leprosy, but lower than that of normal skin tissue. 2. In HLA-A, B, C expression of the inflammatory cells, the level of borderline tuberculoid leprosy is higher than that of borderline lepromatous leprosy and of normal skin tissue(p>0.05). 3. Expression levels of HLA-DP, DQ. DR on endothelial cells decrease significantly in order of normal tissue, borderline tuberculoid leprosy, borderline lepromatous leprosy. lepromatous leprosy(p<0.05). 4. Expression levels of HLA-DP, DQ, DR on inflammatory cells decrease in order of lepromatous leprosy, borderline lepromatous leprosy, borderline tuberculoid leprosy, normal tissue, but statistical significance did not exist. 5. In immunohistochemical stains of CDIb, 3 sections of all 4 normal skin sections and 1 section of 3 borderline tuberculoid leprosy sections showed focal positivity on the denial inflammtory cells,