Abstarct: Hablehrood River is one of the main rivers in Semnan province with three branches; Namrood, Goorsefid, and Delichay. In this study, the concentration of heavy mextals (lead, zinc, copper, iron, chromium, nickel, and cadmium) was evaluated in the water and sediment samples of the river (Branch Namrood to Dalichai). In order to measure the physicochemical properties, heavy mextals concentration, water quality parameters (concentrations of major cation and anion, pH, EC), 15 water and 15 sediment samples were collected. In terms of geology, Cenozoic and Mezozoic sedimentary rocks have outcrop in the study area. The results of water quality investigations showed that the quality of water in Hablehrood (branches Namrood and Delichay) was influenced by carbonate and evaporate outcrops of the region. Interpretation of water quality data reveals that main hydro-chemical type of water is bicarbonateand the face is calcic and magnesic. Water is classified as very hard. Water is in the range of moderate and good for agricultural and Acceptable for drinking. The pH indicated alkaline water. Saturation Index of the samples was under-saturated with regard to halite and gypsum while it is over saturated by calcite, dolomite, and aragonite. The heavy mextals in river water samples showed that among the target elements namely lead, zinc, copper, iron, chromium, nickel, and cadmium, the level of lead in some stations was higher than the standard limit for drinking water (WHO, 2011). Sedimentology studies revealed that sediment texture varies from gravel to sandy mud along the river. Average organic matter and carbonate calcium in the sediments were 0.93 and 3.13 percent respectively. Lead and cadmium levels in the sediments of Hablehrood were higher than the world sediments average. Enrichment factors of Pb and Cd were higher than the other elements. Geo-accumulation index showed amoderate pollution by cadmium. Pollution factor indicated average contamination of lead and significant contamination of cadmium in sediments. According to modified contamination degree, sediments of Hablehrood are none-contaminated to low-contaminated but not contaminated baxse on pollution load index. Sediment quality factor revealed that the concentrations of these elements in sediments did not reach to the probable effect level to affect the benthic organisms. Result of statistical analysis demonstrated that the origin of copper, iron, cadmium and chromium are mainly natural and sources of Pb and Zn are mainly anthropogenic.