Like other organs such as artery, bladder and left ventricle, human intact gallbladders (GB) possess viscoelasticity/hysteresis in pressure-volume curves during in vitro or in vivo dynamic experiments made by using saline infusion and withdrawal cycle to simulate GB physiological emptying-filling cycle in normal and diseased conditions. However, such a viscoelastic property of GBs hasn't been modelled and analysed so far. A nonlinear discrete viscous model and a passive elastic model were proposed to identify the elastic, active and viscous pressure responses in the experimental pressurevolume data of an intact GB under passive and active conditions found in the literature in the paper. It turns out that the elastic, viscous and active pressure responses can be separated in less than 2% error from the pressure-volume curves. The peak active state in the GB occurs at 30% dimensionless volume.The GB stimulated with cholecystokinin (CCK) or treated with indomethacin is subject to almost constant stiffness at low dimensionless volume ( ≤ 70%) but quick increasing stiffness at high dimensionless volume (>70%) and a larger work-to-energy ratio (0.57-0.61) compared with the normal GB in passive state. The models are sensitive to the change in biomechanical property of the GBs stimulated or treated with hormonal or pharmacological agents, showing a potential in clinical application. These results may contribute fresh content to biomechanics of GBs and be helpful to GB disease diagnosis.