The H and O isotope compositions of water from the Yellow River were investigated in this study. The samples were collected at 24 hydrological stations along the mainstream of the Yellow River, from the source region to the Bohai Sea, during July 2005. The δD and δ18O values of water samples vary from -91~ -44‰ and -12.4~ -4.2‰ respectively. The δD and δ18O values both increased gradually from the upper reaches to the lower reaches, except for the sample from No. 1 station. The correlation between δD and δ18O follow an equation of δD=5.69δ18O-15.51. The slope of this equation (5.69) is lower than the slope of meteoric water line for the Yellow River basin (δD=6.71δ18O-5.96), and much smaller than that of meteoric water line in China (δD=7.9δ18O+8.2). It is infered that the δD and δ18O value is mainly affected by by the arid natural environment of the Yellow River. When precipitation fell to the surface, the mount of runoff is greatly reduced by dams, industrial and agricultural water. The evaporation of the Yellow River itself and water circulation use for a long time cause further evaporation. At the same time the δD values variation of the Yellow River were discussed, indicating that the values reflect the hydrogen and oxygen isotopic composition characteristics of the Yellow River water impacted by regional environment, trends in precipitation clouds in the migration process and participation degree of regional water vapor circulation.