Constraint on $\Delta g(x)$ at large $x$

We investigate the polarized gluon distribution \Delta g(x) by a global analysis of current DIS data and the \pi^0 data from RHIC-Spin experiments. The \pi^0 data provide a strong constraint on \Delta g(x), so that its uncertainty is reduced. Furthermore, new DIS data of COMPASS and HERMES play an important role in determining \Delta g(x) at large x.