Purpose: Environmental pollution is a world-wide problem, heavy metals belonging to the most important pollutants. The progress of industries has led to increased emission of pollutants into ecosystems. Tajan is one of navigable river in the Northh of Iran. Along the Tajan agricultural industries units such as piping, steel, paint making, paper mill, fish cultivation, abbottiors, electroplating industries drain their astewater into the river. \nMethods: In this study, the concentrations of heavy metals (pb, Cd) in the Tajan river have been determined. Samples were collected from 5 stations along the river, in autumn and winter 2004. Heavy metal concentrations were measured by graphite furnace atomic absorption spectrometry. \nResults:The minimal and maximal concentrations of these metals in autumn were 21.3–82.7, 1.7–3.3μg/l, for Pb, Cd respectively. The minimal and maximal concentrations of these metals in winter were 10.0–20.7, 1.44–41.25 μg/l for Pb, Cd respectively. \nConclusion: The results show that the pollution has increased along the river, down to the estuary at the Caspean Sea.