Mathematical formulation of the stability of orbits in Restricted 3-Body Problems have been described. In this connection the computation of Poincare section method and wavelet analysis has been described with a view to analyze the nature of orbits in Sun-Jupiter system. Further the extension of the work to include the effect of radiation has been discussed. Such a framework has been used to discuss the stability of orbit in Binary stellar system Kruger-60 and RW-Monocerotis.