The objective of this paper is to apply the asymptotic homogenization method (AHM) to determine the analytical formulae for the elastic effective coefficients of a two-phase fibrous composite provided with a periodic structure. In the analysis, the periodicity of the structure is assumed to be much smaller than the elastic wavelength. The fibres are aligned unidirectional with respect to the x3-axis. The constituents are transversely isotropic materials. The results are used to determine numerically the linear elastic behavior of two types of fibre composites. Some comparisons with different experimental results and theoretical models are shown.