The Weak Scale Measurements Constraints on String Models

The derived modular invariant one-loop string effective coupling constant has been used to discuss the weak scale measurement constraints on minimal superstring models, minimal SUSY left-right string models and minimal left-right SUSY string models. The string intermediate gauge symmetry breaking models are proposed. The possible schemes to predict $M_{GUT} = 10^{16}GeV$ and $M_{SUSY}= 1 TeV$ in string models have been discussed. It is also demonstrated that string unification is more restricted by the experiments than any other unification models are.