Key words superconductivity, Ginzburg-Landau equations, initial boundary-value problems, periodic solutions, stability MSC (2000) Primary 35K55, 35B35. Secondary 35B10, 35B40, 35K15, 82D55The time-dependent Ginzburg-Landau equations describe the state of a superconducting material. The case of time-periodic applied magnetic field implies the existence of periodic orbits. Sufficient conditions are given here that, if satisfied, guarantee the stability of some associated periodic solutions.