ABSTRACT In this research, we address the evolution of matrix cracking in viscoelastic cross-ply laminates made of long Carbon Fibre Reinforced Polymer (CFRP). Monotonic tensile tests performed on [03,903]s laminates at 120°C have shown a significant influence of loading rate on cracking development. Several numerical simulations meant to display the effect of possible factors are proposed in turn. First, linear viscoelastic shear-lag approaches using failure criteria are developed to describe cracking evolution as a function of load level, assuming a constant loading rate. Then, a simplified Schapery 1-D model is used to characterize the nonlinear viscoelastic ply behaviour. The Correspondence Principle is applied to compute the time-dependent cracking development. This work shows that the viscoelastic behaviour of undamaged material cannot explain alone the loading rate effect on cracking. On the other hand, the loading rate dependence of critical strength gives good predicted cracking curves, which means that the important rate effect pertains to the damaged viscoelastic material in the process zone close to crack tips.