Objective To explore the value of serum aquaporin 8 (AQP8) expression in evaluating the degree of hydrolabyrinth and predicting prognosis in patients with Meniere’s disease. Methods 105 patients with Meniere’s disease in our hospital were included in the Meniere’s disease group.Another 102 healthy subjects in our hospital were included as the control group. The multivariate Logistic regression was used to analyze the influencing factors of poor prognosis in patients with Meniere’s disease. Results The expression of serum AQP8 mRNA in the Meniere’s disease group was greatly higher than that in the control group (P<0.05). Serum AQP8 mRNA expression in severe hydrops group was greatly higher than that in mild hydrops group and no endolymphatic hydrops group, and serum AQP8 mRNA expression in mild hydrops group was greatly higher than that in no endolymphatic hydrops group (P<0.05). The course of disease, the proportion of severe hydrops and the expression of serum AQP8 mRNA in the poor prognosis group were greatly higher than those in the good prognosis group (P<0.05). The area under the curve (AUC) of serum AQP8 mRNA for predicting poor prognosis in Meniere’s disease patients was 0.812 (95%CI: 0.702-0.922), with a sensitivity of 81.0% and a specificity of 70.2%. AQP8 mRNA was an independent risk factor for poor prognosis in patients with Meniere’s disease (P<0.05). Conclusion AQP8 mRNA is associated with the degree of hydrolabyrinth in patients with Meniere’s disease, and has a high performance in predicting prognosis.