Abstract: Reservoirs and urban construction have changed the natural attributes and underlying surface characteristics of river basins, thus affecting the water cycle of basins. Taking the Huangshui River Basin as the research object, the river sections were divided based on different land use patterns and reservoir characteristics, and water samples were collected respectively, and the hydrogen and oxygen isotopic compositions of the Huangshui River water and their distribution characteristics were analyzed. The results showed that the hydrogen and oxygen isotope (δD and δ18O) values of river water in urban areas and reservoir were significantly higher than those in non-urban areas and inflowing water. In order to explore the universality of the phenomenon, the isotopes data of reservoirs and urban areas in previous studies were extensively collected. The study found that in the reservoir-affected area, the difference between the stable isotope values of the reservoir water and the inflowing water was positively correlated with the reservoir surface area and retention time; in the urban impact areas, the difference between the stable isotope values of the urban water and the non-urban water was positively correlated with the proportion of artificial surface area around the river. This indicates that reservoir and urban construction have promoted the evaporation and fractionation of hydrogen and oxygen isotopes in the river water. This study used the stable isotope method to analyze the impact of reservoir and urbanization on the river water cycle, which has reference significance for studying the characteristics of water cycle under influence of human activities at the micro scale.