Geothermal heat has been identified as a renewable and reliable energy source comparative to the conventional fossils. Understanding of temperature dependent mechanical behaviour of geothermal reservoir's rocks is however necessary for a safe and effective geothermal energy extraction. This has been studied in this study with experimental evaluating the effect of temperature on mechanical behaviour of Australian Strathbogie granite and then modeling the findings for a broader conditions. The experiments were first conducted with heating the rock samples to various temperatures and then uniaxially loading the heated samples until the failure. Experimental results clearly showed how the UCS strength of the tested granite varies with temperature, where increasing of temperature leads an initial increment in reservoir rock's compressive strength and elastic modulus followed by their significant reductions. A finite element model was then developed with incorporating the measured temperature dependent stress stain data using ABAQUS to predict the temperature dependent mechanical behaviour of granite over a wide range of temperatures.