Abstarct: The Gorganroud River is is one of the most important rivers of Golestan province. A part of this river flows through Gonbad-Kavous City. In order to study of water quality and assessment of microbial and mextal pollution of this river 12 water sample between Golestan Dam and Voshmgir Dam were collected in November 2014. Physciochemical parameter (pH, electrical conductivity, TDS), concentration of major ions and some mextals (Fe, Mn, Cu, Al, Pb and Cr) and biological parameters were analaysed by standard methods. The obtained results show that pH of the water samples varies from 7.39 to 8, and lowest pH observed within the city. The electrical conductivity of water samples varies from 2030 to 5950 μs/cm and highest value observed in S2 station, probably duo to low volum and velocity of water in this part of river. Concentration of Na+, Cl-, Mg+ and SO42- ions are higher than permissible limit for drinking. baxse on results obtained from calculate mineral saturation indices, ions ratios and Durov and Gibbs diagrams, the chemistry of water is dominantly controlled by dissolustion and mixing process. According to stiff and pipper diagram, it was founded that water type in up stream and downstream, respectively is Na-SO4 and Na-Cl. baxse on scholler and willcox diagram all water samples are inappropriate for drinking and irrigation. baxse on Magnesium hazard all of water samples are unsuitable for agricultural usages. According to calculated values for residual sodium carbonate and sodium percent parameters all of samples are suitable for irrigation. In all stations concentration of Iron ans Aluminum and also concentration of Lead, manganese and Chromium in some stations are higher than WHO standards for drinking water. Calculation of mextal index shows that all of water samples are polluted with mextals. baxsed on calculated values for HPI and Cd indices, all of samples extremely polluted and samples collected within Gonbad-Kavus City showed lower values of this indices duo to increase content of organic substance. Amount of dissolved oxygen in all samples are in permissible limit. Biological oxygen demand and chemical oxygen demand values in most samples are higher than permissible limit and highest value of this two parameter observed within the city and after first wastewater discharge. The results show that all of water samples extremely are microbially polluted. Calculated water quality index (WQI) indices (NSFWQI, OWQI, CCMEWQI and said) show that all studies samples are in bad and very bad classes.