Abstract: Based on the test of reactive powder concrete (RPC) with different granite powder replacement ratios, the mechanical properties and micro-structural effect on the standard curing RPC were investigated. Results show that, under the condition of standard curing, along with the increase of granite powder replacement ratio, the mechanical properties of RPC can satisfy the requirements of the former. After standard curing 28d, granite powder completely replaces quartz powder, compared with the case of no replacing, the microstructure of hydration products is given priority to the needle bar of C-S-H, which the length of the C-S-H is about 3μm with slightly different in Ca/Si ratio. Standard curing RPC pore structure is given priority to with harmless hole and little hole. The RPC pore structure was improved after quartz powder was replaced by granite powder.