  We present a bottom-up approach to the question of supersymmetry breaking in
the MSSM. Starting with the experimentally measurable low-energy supersymmetry
breaking parameters, which can take any values consistent with present
experimental constraints, we evolve them up to an arbitrary high energy scale.
Approximate analytical expressions for such an evolution, valid for low and
moderate values of $tan\beta$, are presented. We then discuss qualitative
properties of the high-energy parameter space and, in particular, identify the
conditions on the low energy spectrum that are necessary for the parameters at
the high energy scale to satisfy simple regular pattern such as universality or
partial universality. As an illustrative example, we take low energy parameters
for which light sparticles, within the reach of the LEP2 collider, appear in
the spectrum, and which do not affect the Standard Model agreement with the
precision measurement data. Comparison between supersymmetry breaking at the
GUT scale and at a low energy scale is made.
