The objective of this study was to clarify the effect of fuel moisture content (FMC) upon the behaviour of surface fire propagating through homogeneous vegetation stratum. This problem was approached using numerical simulations performed in 2D at relatively large scale (the dimensions of the computational domain are: 170 m long and 35 m high). The mathematical formulation was based on a CFD multiphase approach, in which the vegetation was assimilated as a sparse porous media immersed in a gas phase (the atmosphere) (Grishin 1997, Morvan et al 2009). The numerical results have been analysed in terms of fire residence time, fire front depth, fuel lean / fuel rich conditions, mass loss rate and rate of spread (ROS). Two windy conditions (calm and weak) were studied to evaluate the decay of the rate of spread (ROS) resulting from an increase of the fuel moisture content. The numerical results have highlighted that for calm wind conditions (U10 = 1 m/s), the FMC affected the propagation of the fire in reducing the rate of pyrolysis (fuel limited regime), until reaching the extinction observed for FMC around 20%. Whereas for stronger wind conditions (U10 = 4 m/s), a propagation can be observed for values of the FMC much larger than this critical value and in this case, the presence of a large amount of water vapour ahead of the fire front contributed to reduce the supply in oxygen of the combustion zone (oxygen limited regime) (see Figure 1). The existence of these two regimes of propagation can be also highlighted in Figure 2 representing the evolution of the fire residence time versus the FMC for two values of 10m open wind velocity. The effect of wind velocity upon marginal burning conditions was also analysed. The numerical results were also compared with empirical data of the literature (Morvan 2013).