In the research, determination of principal and non-principal monitoring stations was carried out using principal component analysis (PCA) technique for the Maroon River, Iran. Also canonical correlation analysis (CCA) was used to determine relationship between physical and chemical water quality parameters. Water quality parameters including BOD5, COD, EC,NO3-, SO4-2, temperature, Cl-, DO, hardness, TDS, pH, and turbidity were measured in samples collected from 17 stations along Maroon River from 1999 to 2002. Four of our monitoring stations proved less telling in explaining the annual variation of the river water quality, and were removed. Further investigations indicated that all water quality parameters were important. In CCA, the first four canonical correlations were 0.993, 0.822, 0.785, and 0.660, respectively, suggesting that EC and TDS were two dominant physical parameters in the all canonical variates whilst ions and hardness were highly scored from chemical parameters. Verifying the ability of PCA and CCA methods was carried out by simple regression and correlation methods, respectively. (C) 2010 Elsevier B.V. All rights reserved.