The pollution by heavy metals of Hg, Cd, Cr⁶⁺, Pb, As, Cu, Zn and Se in the Weihe River of Xi'an section were analyzed using the methods of single factor water quality assessment and heavy metal pollution index(HPI). The health risks of these metals were evaluated by the method documented by USEPA. The results indicated that Pb and Cd were undetectable in all water samples, but the water was contaminated to certain degrees by Hg while all other metal contents were within the limits of the categoryⅠor Ⅱ of surface waters based on the Environmental Quality Standards for Surface Water (GB3838-2002). The HPI of the water of the river in the region was 32.74, which was lower than the threshold value of 100, indicating that the pollution is within the acceptable level. The results also showed that the non-carcinogenic risk and the carcinogenic risk of the investigated metals are acceptable, and the highest carcinogenic risk was from As in the water body, with the risk index being at 8.50×10^-5. It suggests that As in water of the region should be of specific concern for the local environmental monitoring and management authorities, since its health risk index was almost close to the upper acceptable limit(10^-4).