The invention relates to a coupling member for the mechanical and electrical connection of lighting device in line and/or angled for the formation of lighting system. The coupling includes a junction body (11) having more sides and on each side mechanical connecting means (18) and an electrical end connector (16), which link up with complementary elements, both mechanical (23) and electrical (21), at the edges of each lighting device (19) to be connected. The junction body bears four sides and the electrical connector along the sides are precableable.