At prospective e^\pm e^- linear colliders (LC), supersymmetric particles can be produced copiously. Large production cross-sections of kinematically accessible sparticles and clean signatures will allow for very precise measurements of their masses and couplings and the determination of their quantum numbers. We discuss some methods and expected accuracies in determining low-energy parameters of the supersymmetric model from the high-precision LC data and from combined results of LC and LHC. Evolving the parameters from the low-energy scale to the high-scale, the fundamental supersymmetry parameters can be reconstructed to reveal the origin of supersymmetry breaking.

PACS numbers: 11.30.Er, 12.60.Jv, 13.10.+q