This research examines the eutrophication process mainly by considering the chlorophyll-a concentration. A simple linear model was used to determine the correlation between chlorophyll-a and dissolved inorganic phosphate (DIP). The research was carried out on some river mouths in the north coast of Central Java. The results of the linear model show that the relationship between chlorophyll-a and DIP follows the logarithmic model with the log [Chlo-a] = 1.52 + 1.60 log [DIP], R2 = 0.55. The model suggests that the high concentration of chlorophyll-a is related to dissolved inorganic phosphate concentrations. Based on the sufficient of conclusive evidence for these variables, the study sites with high stresses from several anthropogenic sources had higher chlorophyll-a than study sites that are relatively far from river mouths and lands.