Abstract: The invention refers to a modular hydrokinetic assembly which allows the conversion of the kinetic energy of flowing waters into useful mechanical energy for driving some electric generators or water pumping sets, without building dams or culverts. The modular hydrokinetic assembly according to the invention comprises two lower and upper underframes (1 and 2) and a blade assembly (3) formed of two endless chains comprising the plates (20) whereon blades (21) are fastened and actuated by the water of a river, caught from a river by means of a threshold and catching connector and, transmit the mechanical energy by means of a star wheel (23), secured on the axles of electrical generators (4) or water pumping sets (5), the amount of the resulting mechanical energy being dependent mainly on the water flow rate and slope of the channel formed by the lower underframe (1) and, by the radius described by the blades (21) to the axles of the star wheels (23).