CTEQ5 parton distributions and ongoing studies.

The CTEQ5 parton distributions are described, with emphasis on the changes since CTEQ4. The most significant change is in the quark flavor dependence of the parton distributions. Ongoing studies of large-x parton distributions are discussed. Luminosity estimates are given for HERA in order to improve the present uncertainties of the quark distributions. A discussion of how to improve the gluon uncertainty in the future is presented