A combined finite element method and inverse modelling approach is used to model the mechanical deformation of onion epidermis. A fibre-reinforced hyperelastic composite material model considering the fibre distribution has been used to simulate the mechanical behaviour of samples under tension. The mechanical parameters of onion epidermis are determined using an inverse modelling approach. The simulated results show a good correlation with experimental observations. (C) 2010 Elsevier Inc. All rights reserved.