Any kind of life requires water, to provide a suitable for drinking and urban public usages, series of operations are applied in the water treatment plant, to deliver the received water from sources as water with acceptable quality standards of “drinking water”. There are various methods for water and wastewater treatments and they are used depending on the water consumption and the kind of contaminant it has. One of the most important methods for turbidity and organic matter removal from raw water sources, is to coagulate the waste material of the water with coagulants. This study was done to evaluate the performance of coagulants poly aluminum chloride (PACL) and ferric chloride ferric chloride (FeCL3) in reducing turbidity and organic matter from the raw water source of Ardebil’s treatment plant. This experimental-analysis study was done using a Jar test machine. Studied samples were taken from a raw water transmission pipeline, from Yamchi dam to Ardebil’s treatment plant, in four seasons of year 2014. In order to conduct a qualitative and quantitative research process, more than 48 samples were tested in spring, summer, autumn and winter, respectively with turbidities of 17-21-13-7 NTU, by coagulants poly aluminum chloride (PACL) and ferric chloride (FeCL₃) results showed that coagulant poly aluminum chloride had a better performance than ferric chloride in using less coagulant materials, making bigger flocks, reducing the sludge settling time and creating sludge with high adhesion. Assigned to the removal of dissolved organic matter of the water (DOC), coagulant poly aluminum chloride was able to remove the highest amount of DOC from samples, at a rate of 7 percent. The results showed that, in Ardebil’s water treatment plant, PACL can be a suitable alternative for low consumption of coagulants and removing organic matter of raw water, more than coagulant ferric chloride.