Extreme hydro-meteorological events occur more frequently with global warming, which have a great impact on ecology, environment and hydrology. Hydrometeorological variables often exhibit disturbances of non-stationary characteristics.In this paper, we take a typical ecological function reserve (Poyang Lake Basin) as an instance to study the trend and probability characters of extreme streamflow based on stationary and non-stationary generalized extreme value (GEV) models. Time and large-scale climate factors such as Southern Oscillation (SO), North Atlantic Oscillation (NAO), Arctic Oscillation (AO), Pacific Decadal Oscillation (PDO), Atlantic multidecadal oscillation (AMO), NINO3 SST (NINO3) and NINO3.4 SST (NINO3.4) are incorporated as covariates to establish non-stationary model. The main results