  We review and extend high energy string BCJ relations in both the fixed angle
and Regge regimes. We then give an explicit proof of four point string BCJ
relations for all energy. This calculation provides an alternative proof of the
one based on monodromy of integration in string amplitude calculation. In
addition, we calculate both s-t and t-u channel nonrelativistic low energy
string scattering amplitudes of three tachyons and one leading trojectory
string state at arbitrary mass levels. We discover that the mass and spin
dependent nonrelativistic string BCJ relations can be expressed in terms of
Gauss hypergeometry functions. As an application, for each fixed mass level N,
we derive extended recurrence relations among nonrelativistic low energy string
scattering amplitudes of string states with different spins and different
channels.
