Abstract: Objective To investigate the roles of Dectin-1 and caspase recruitment domain-containing protein9 （CARD9） genes in the response of HaCaT cells against Trichophyton rubrum. Methods In this experiment, Trichophyton rubrum was co-cultured with HaCaT cells, Dectin-1^-/- HaCaT cells and CARD9^-/- HaCaT cells, respectively. The expression levels of IL-6 and IL-8 in the cell supernatant were assessed by ELISA. Results Dectin-1 gene knockout resulted in a significant increase in the secretion of IL-6 and IL-8（both P < 0.05）, CARD9 gene knockout increased the secretion of IL-6 in HaCaT cells（P < 0.05）. After the infection of Trichophyton rubrum, the secretion of IL-8 was significantly decreased in HaCaT cells（P < 0.05）. Dectin-1^-/- HaCaT cells showed a significant decrease of IL-6 and IL-8（both P < 0.05）, whereas no evident change was observed in the secretion of IL-6 and IL-8 in CARD9^-/- HaCaT cells（both P > 0.05）. Conclusions Dectin-1 and CARD9 genes may play an important role in maintaining the immune homeostasis of the epidermis. CARD9 gene may be involved in mediating the immune response against Trichophyton rubrum.