Abstract: In order to study the mechanical behaviors of recycled coarse aggregate concrete under tri-axial compression, 36 cylinder specimens were designed for conventional tri-axial tests, and two parameters were considered in the tests, namely the replacement ratio of recycled coarse aggregate and lateral confinement. The failure patterns of the specimens were observed, and the stress-strain curve and characteristic parameters (such as peak stress and peak strain) were obtained by the test. Based on the test data, the influence of the replacement ratio and lateral confinement on tri-axial compression mechanical performance was analyzed, and some formulae for initial elastic modulus, vertical peak stress and peak strain in different confinement value were put forward. The experimental study shows that the replacement ratio of recycled aggregate concrete has little influence on the peak stress and peak strain in tri-axial compression, but has great influence on initial elastic modulus. Compared with natural concrete, peak stress variation range is about 5%, peak strain variation range is about 2%, and the elastic modulus increased about 20%. Lateral confinement value significantly impacts the technical specifications of the recycled concrete under tri-axial compression, and increasing lateral confinement value can effectively improve the elastic modulus, bearing capacity, and deformation performance of recycled concrete.