To investigate the expression of vaginal IL-23 and its role in experimental murine vaginal candidiasis and its relationship with infection and immune status, immuno-competent (group A) and immuno-suppressed (group B) murine models of vaginal candidiasis were established in estrogentreated mice. Non-estrogen-treated mice were used as controls (group C). The level of IL-23 p19 mRNA in murine vaginal tissue was determined by RT-PCR. Significantly increased levels of IL23p19mRNA were observed on the 4th, the 7th and 14th day after inoculation in immuno-competent group when compared with that in control group (P＜0.01, P＜0.05), However, significant increase of IL-23 p19mRNA were only observed on the 7th day and the 14th day after inoculatuon in immuno-suppressed groups (P＜0.05). On the 4th and 7th day, the levels of IL-23 p19mRNA were significantly increased in immuno-competent group than those in immuno-suppressed group (P ＜0.05). Local IL-23 may play a role in the pathogenesis of murine vaginal candidiasis and has a protective function during infection. Low vaginal IL-23 level may correlate with the increased susceptibility to Candida albicans in immuno-suppressed group.