Abstract: Since at present the methods of flood season-ality determination are subjective and inaccurate, this paper focuses on comparing and evaluating three models for determination of flood seasonality. The change point analysis theory is used to divide the flood period into several segmentations through three different sampling methods, which include daily maximal (DM), annual maximal (AM) and the peaks-over-threshold (POT) models. Monte Carlo experiments show that the change point analysis is an objective method and can obtain rational and accurate flood seasonality. Its also shown that change point analysis with the POT sampling method can obtain best effect with the least bias and highest efficiency among these models.