The present study was carried out in 2011 to measure concentration of heavy metals chromium and tin in liver and muscle tissue of Liza aurata (golden grey mullet) in estuaries of the rivers Babolroud, Tajan and Gorganroud. Accordingly, after sampling the target are asandisolating muscle (18samples) and liver (18samples) tissues, they were digested and analyzed using Graphite Furnace Atomic Absorption Spectrometer (GFAAS). Then, the obtained data were analyzed statistically using Spss19. The results indicated that the concentration of the metals in liver was higher than the muscle tissue. The highest concentration was related to the tin metal in liver tissue of the golden grey mullet measured from Gorganroud Area while the lowest concentration was related to chromium reported from the estuary of Tajan River. Asignificant difference (P<0.05) was observed between the concentrations of chromium metal in liver and muscle tissue. No significant difference was recorded between the concentrations of tin metal in liver and muscletissue of golden grey mullet (P>0.05). At the end, relationship between weight, length and average concentration of tin and chromium in liver and muscle tissue of golden grey mullet were analyzed by Pearson'stest. A significant reverse linear correlation wasfound between concentration of tin and the weight (p<0.05).