Peanut is among the most commonly used dietary seeds, but peanut allergens, especially Ara h 1 (Arachis hypogaea allergy 1), 2 and 3, can cause severe IgE-mediated reactions. In this study, the molecular characterization and expression pattern of three allergens in peanut LUHUA 8, the representative of the cultivated lines in China, are reported. In situ hybridization and real time PCR analysis revealed high expression levels and different tissue expression patterns of the three allergens, which might be connected with many aspects, such as the strong conservation of intron phase of the allergen genes, the low energy of the mRNA's regions, and the complicated post-translational modifications. Furthermore, the different sequences between the cloned allergens and the reported sequences previously involved the charged amino acids especially in IgE epitopes, which might alter specific physicochemical and physiological properties, and thus influence the immunity of the allergens. The identification of the specific features of the allergen genes would be of considerable importance to the basic understanding of the specific characteristics of peanut seed allergens.