  We present a prescription for generating pure spin current or spin selective
current, based on adiabatic quantum pumping in a tight-binding model of a one
dimensional conductor. A formula for the instantaneous pumped current is
derived without introducing the scattering matrix. Our calculations indicate
that some pumping cycles produce the maximum value 2 of pumped spin while
others reverse the direction of current as a result of small alterations of the
pumping cycle. We find pumping cycles which produce essentially any ratio of
spin current to charge current.
