The properties of graphene have stimulated interest in the two-dimensional materials with similar properties, but having a bandgap. Transition metal dichalcogenides (TMD) are very promising candidates for a new generation of opto- and microelectronic applications due to strong dependence of mechanical or electrical properties on chemical composition. TMDs such as MoS2, MoSe2, WSe2 and WS2 have a bandgaps, which can be changed from indirect to direct in single layers, allowing their application as transistors, photo- and electroluminescent devices [1].     TMDs exist in bulk form as multilayered structures with very weak interlayer attraction, which allow to use both chemical and mechanical exfoliation to produce two-dimensional TMD layers of different thickness. The most important properties of the material can be controlled by changing the thickness of the layer: the optical transitions, conductivity, electron mobility, electron relaxation parameters. Lateral size of 2D flakes is about several microns, and therefore mapping microscopic technique may be used to find the flakes. To study the dynamics of the processes in such structures pump-probe technique is traditionally used.   In our measurements Ti:Sap femtosecond laser system with pulse width of 30 fs and wavelength of 800 nm was used to produce probe beam. For the pump beam, the second harmonic of the probe radiation was used. In pump-probe experiments, linear reflection depending on the time delay of the probe pulse relative to the exciting were measured. The experimental dependences were approximated within the two-time model that contains ultrafast (at the order of 1 ps) and fast (a tens of picoseconds) components. Ultrafast relaxation time is related to the time of redistribution of excited electrons between conduction bands according to the thermodynamic distribution, and slower time is fast relaxation time is related to the carriers recombination of the conduction band to the valence band.   This work is supported by Russian Science Foundation Grant №14-12-10080