Self-compacting concrete (SCC) provides high flowability, high filling capacity, high passing ability through reinforcing bars, which are owned by using a powerful superplasticizer as well as reducing both the coarse aggregate content and water/powder ratio. It should also expose high segregation resistance, which can be obtained by using high amount of fine material or by adding a viscosity modifying admixture, or both. In this study, the rheological properties and segregation resistance of SCC are examined. The effect of coarse aggregate concentration between 225-375 dm(3)/m(3) on both flow behavior and segregation resistance of SCCs are investigated on concretes prepared with cement and fly ash as binder. The total binder content (including both cement and fly ash) varies between 450 and 650 kg/m(3). The maximum aggregate sizes were chosen as 12, 16 and 20 mm. In the experiments a specially designed apparatus, which was expired from the slump-flow and L-shape box tests, has been used. This apparatus also allows the measurement of segregation resistance. The other tests applied were slump-flow and penetration resistance.