Abstract: Cyclic loading tests on behavior of concrete prisms subjected to large compressive strains of different amplitudes were carried out in an effort to identify the low cycle fatigue behavior and to formulate constitutive relationship of such concrete prisms under large compressive strains.The experiments were undertaken by using INSTRON digital electro-hydraulic servo testing system.The amplitude of controlled strains under each loading stage was specified on the basis of peak steain ε₀,and the number of cycles ranges from 624 to 8931.Unloading and reloading stress-strain relationships were obtained and unique low cycle fatigue characteristics were identified.