A multi-scale model for concrete transport property prediction is developed by electing representative elements from micro to macro scale. Taking ionic diffusivity prediction as an example， the model comprehensively analyses the influence of inhomogeneity on the transport properties at different levels. Compared with the traditional model， new proposed model not only considers the influence of the hydration process at the microscopic scale， but also further analyses the influence of interfacial transition zones， aggregate shapes and the multi-species ions interaction at the mesoscopic and macroscopic scales. The paper verifies the reliability of the model at each scale by comparing the predicted and experimental results of chloride diffusivities in concrete. Based on the proposed model， transport properties at different scales can be comprehensively revealed and analyzed. The present work also hopes to provide a novel multi-scale framework to predict the transport mechanism of concrete.