We classify all cubic differential systems with a linear center and multiple line at infinity up to multiplicity four. For every class with the multiplicity of the line at infinity four the center problem is solved. It is proved that the monodromic points are of the center type if the first three Lyapunov quantities vanish

Sunt clasificate sistemele diferentiale cubice cu centru liniar si linia de la infinit de multiplicitate cel mult patru. Pentru fiecare clasa ce are linia de la infinit de multiplicitate patru este rezolvata problema centrului. Se arata ca punctele monodromice sunt de tip centru, daca se anuleaza primele trei marimi Liapunov.