Carbonation of cementitious materials is one of the most important reasons leading to the deterioration of steel-reinforced concrete structures. After years of research, different models have been developed to investigate and predict the carbonation process. This review paper provides a comprehensive overview of carbonation modelling approaches at different scales considering pore structure characteristics. As a typical porous material, the microscopic characteristics of hardened cementitious materials will greatly affect the carbonation rate, and the complex physicochemical carbonation process will alter the pore structure, which will, in turn, affect the carbonation process. Currently, the importance of considering the evolved pore structure and its influence on concrete durability modelling has also gained more and more attention. Therefore, this review paper first introduces the fundamental mechanism of carbonation process in cementitious materials and the existing models for carbonation modelling. By dividing these models into macro-, meso- and micro-scales, this review summarises the modelling approaches, assumptions, pore structure consideration approaches and current limitations of the empirical, kinetic, three-phase, neural network, voxel-based lattice, pore network, and thermodynamic models. The different features of carbonation modelling and ways to consider the effect of pore structure characteristics in those models are comprehensively compared. This review also discusses the future perspectives of different models, especially the pore structure-dependent analysis approaches, to better link the microscopic and macroscopic properties and improve the applicability of carbonation modelling at different scales.