Understanding cryospheric hydrology and the effects of cryospheric changes on river runoff is critical for sustainable water management especially in arid inland river basins such as those in northwest China where water resources mainly come from alpine areas. A cryospheric hydrometeorology observation system (CHOICE) has been established since 2008 in the Hulu catchment, which is a well-instrumented experimental and representative catchment in the upper reaches of the inland Hei River, Qilian Mountains, northwest China. The CHOICE includes dense meteorological measurements from 2980 to 4800 m asl (e.g. glacier, snow, and permafrost hydrology) and water and heat balance in the vertical landscape zones including alpine grassland, meadow, shrub, coniferous forest, marshy meadow, and moraine-talus zones. The comprehensive long-term observations available for the CHOICE provide the basis for model development and application in cryospheric hydrological research. We focus on cryospheric hydrometeorological process of precipitation, freeze-thaw cycle, energy balance, soil-vegetation-atmosphere transfer (SVAT), runoff, groundwater reservoir, and hydrological resiliency within vertical elevation in CHIOCE. Data from CHOICE, an open cryospheric hydrology observation and research system, is accessed through a website (http://hhsy.casnw.net/) and the WestDC database (http://westdc.westgis.ac.cn/).Serving as a solid reservoir for many endorheic and exorheic basins (Xiao et al., 2015), the mountain cryosphere is the regulator of major rivers and provides most of the water resources in arid regions in China and its neighboring countries. Moreover, the mountain cryosphere is very sensitive to climate change, and its changes can have significant impacts on the hydrological cycle and water resource management in arid endorheic basins. However, because of inadequate observation data and the lack of knowledge about many aspects of cryospheric hydrometeorology at regional scales in alpine regions, the significance of the impacts of cryospheric changes and the severity of their consequences remain unclear in China (Chen et al., 2015, 2018bLi et al., 2018). In alpine regions, the key goal is to understand environmental changes (Guo, 2018) and their effects (Qin and Xiao, 2009) using observations, models, and other techniques.As a result, a cryospheric hydrometeorology observation system has been established since 2008 in the Hulu Catchment (CHOICE) upstream of the Hei River Basin, Qilian Mountains, northwest China (Chen et al., 2014). The CHOICE is an integrated observation system used to observe alpine hydrometeorology in a small catchment with evident vertical landscape zones. Alpine meteorology, cryospheric hydrology, and water balance data on different land covers, groundwater, and streamflow are included. This paper provides an overview of the CHOICE.