Aluminum-Boron carbide (Al-B4C) composites containing Al-0, 5, 10 and 15 wt% B4C were produced by flux assisted reaction method at 900°C. In order to study the effects of temperature on flow property and microstructural evolution, compression tests were done over the temperature range of 25° to 500°C at an initial strain rate of 10-2 s-1 and the microstructures were examined in Scanning Electron Microscope. The stress-strain curves exhibit an increase in flow stress with the B4C content, except that the same decreased for Al-15 wt% B 4C composite below that of Al-10 wt% B4C composite. The flow stress was found to decrease with the increase in test temperature above ∼200°C, but it exhibited nearly athermal behavior below this critical temperature. The flow property of the composite is discussed in terms of the flow of the matrix and particulate, and the concurrent microstructural evolution that occurs during deformation.