In this study, the effects of fly ash obtained from Soma, Çatalağzı and Tunçbilek thermal power plants on the compaction and strength properties of the fine-grained soil on which the core part of the Kunduzlar soil dam is built were investigated. Optimum water contents were determined by adding 5%, 10%, 15%, 20%, 25% and 30% fly ash additives to the ground. Samples prepared at optimum water contents were subjected to shear box and unconfined pressure tests. As a result of the study; It was determined that the optimum water content of the soil increased and the maximum dry density decreased as the contribution rates of the fly ash taken from all three thermal power plants increased. When the unconfined compressive strengths were compared, it was determined that Tunçbilek and Çatalağzı fly ash reached the highest strengths at 10% and Soma fly ash at 5%. Among the fly ash used, the highest strength was obtained in the 5% contribution of Soma fly ash. When the shear strengths are compared, the highest strength was observed in Tunçbilek and Çatalağzı fly ash with an admixture of 10% and in Soma fly ash with an additive rate of 5%.