NOVELTY - The system has metallic supporting rail, central profile supporting rail, perimetric profile supporting rail and transverse profile supporting rail which are provided for forming assembly of profiles (1,2,7). The profiles are mutually fixed by suitable components, so as to form rectangular-shaped seals for removable insertion of photovoltaic modules which are laid in horizontal or inclined planes, such that the transversal supporting base profiles (1,7) are opened upwardly in rectangular section.    USE - System for assembling photovoltaic module on ground/top of building.    ADVANTAGE - The simplified installation and maintenance are achieved. The installation time is reduced due to the ease of installation and use of templates for the installation of the profile rails, the simplicity of finish metalwork is attained. The electrical cable is provided along the slope through holes of the supporting profile rails. The modules of any size are mounted flexibly.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for system has central supporting profile rail has a base profile (1) on which the underlying profile (2) is mounted, by means of snap, support portion and threaded seat. Central locking device has support portion arranged specularly with respect to screwing connection unit (4), and covering element (5). A base profile (7) has a threaded seat and support portion for the engagement of a perimetric crankcase provided with a coupling device for coupling base profile and seat. A perimetric locking device is provided with a support portion and coupling portion which are inserted in a seat of housing and overlying housing for eventual insertion and locking of flashing portion. The transverse profile rails are aligned and arranged on the base profile orthogonally to form the perimeter of rectangular-shaped seats, for the insertion of photovoltaic module. The photovoltaic modules are arranged laterally on one side of each perimetric supporting profile rail and are secured by screwing locking perimetric device on the underlying profile rail. Covering element is snapped on perimetric locking device and photovoltaic modules. The rectangular section with top opening is mutually connected in longitudinal and transverse directions for forming channeling of the water for condensation. The underlying profile rail is inserted in suitable holes of locking devices and screwed into the conjugate threaded holes obtained in underlying profiles. The profile rails are formed of aluminum material.    DESCRIPTION OF DRAWING(S) - The drawing shows a side schematic view of the photovoltaic module assembling system.    Base profiles (1,7)    Underlying profile (2)    Central locking device (3)    Covering element (5)    Photovoltaic module (M)