Abstract : The main objective of this study is to investigate the transverse cracking kinetics in [0m/90n]S cross-ply laminates made of IM7/977-2 or IMS/M21 composite systems, which are used in the aeronautic industry, from monotonic or cyclic tensile tests performed at several temperatures. An energetic cracking criterion is used. Several strain energy release rate expressions are compared, in order to obtain a realistic curve of fracture energy versus crack density. The influence of delamination and temperature on the cracking curves (crack density versus applied stress) is also considered. For the IM7/977-2 composite sysstem, the temperature effect can be accounted for using the time-temperature superposition principle, by constructing master curves of equal damage. A transition from monotonic cracking to fatigue cracking is investigated. Experimental results and simulations of transverse crack growth during fatigue tests are presented. The cracking criterion uses a fracture energy expression stemming from an extension of Vinogradov's model which relies upon a simple assumption regarding the shape of first cracking S-N curves, and takes into account the R-curve effect.