  N=1, D=4 Superstring possessing $SO(6)\otimes SO(5)$ symmetry action and with
the same gauge symmetry obtained from zero mass spectrum of vector meson as
well, is constructed from the bosonic string in twenty six dimensions. Without
breaking supersymmetry, the gauge symmetry of the model descends to the
supersymmetric standard model of the electroweak scale in four dimension.It is
proved that there can be three generations in the model
