The goal of this research is recognition of species of pollution and a rough estimate of rate of transmitted pollution through northern Iran rivers to Caspian sea. Sampling from 3stations up-river, mid-river, and down-river in Lavij rood, Gland rood, and Sabze rood in a 6 month period from 2008/5/22 to 2008/11/22 coincides with warm, low rain, cold and rainy seasons and parameters as temperature, electrical conduction, solved
turbidity, BOD,COD, with concentration of main cations and anions and microbiological parameters were measured.
On the basis of piper diagram water of 3rivers in rainy and low rain seasons are from kind of magnesium bicarbonate.
The analysis of measured parameters according to N.S.F program showed that the total quality index in first 3month in low rain seasons is lower than 50 and it means poor quality. In second 3month in rainy seasons this index is upper than 50 and it means the medium quality of water.
The classification and determination of the quality of water considering central committee standard of India pollution control with results of N.S.F method is in harmony.