Many constitutive models for unsaturated soils have been reported, but only a few have attempted to incorporate the influence of soil structure, which is a combination of fabric and bonding. Some important aspects of unsaturated and structured soils (e.g., cemented soil and loess), such as the effects of soil structure on the loading collapse (LC) curve, cannot be well captured by the existing models. According to experimental results in the literature, the inclination of the LC curve of structured soils can be either smaller (Case-I) or larger (Case-II) than that of reconstituted soils. Case-I is usually observed in cemented soils, whereas Case-II is often reported for intact soils (e.g., loess). Based on the above observation, a new model is developed for structured soils under saturated and unsaturated conditions based on two reference models[1,2]. Several new equations were proposed to model (i) the influence of soil structure on the LC curve; (ii) the evolution of the LC curve during structure degradation. Moreover, the structure effects on the dilatancy are considered. The initial soil structure and its evolution under hydro-mechanical load can be properly simulated. The proposed model is verified by simulating the behaviour of structured and unsaturated soils along different suction and stress paths, including constant-stress wetting, constant-suction isotropic compression, one-dimensional compression and triaxial shearing. The measured and computed results are well matched, demonstrating the good capability of the proposed model.