  In this paper, we prove the global existence and uniqueness of solution to
d-dimensional (for $d=2,3$) incompressible inhomogeneous Navier-Stokes
equations with initial density being bounded from above and below by some
positive constants, and with initial velocity $u_0\in H^s(\R^2)$ for $s>0$ in
2-D, or $u_0\in H^1(\R^3)$ satisfying $|u_0|_{L^2}|\na u_0|_{L^2}$ being
sufficiently small in 3-D. This in particular improves the most recent
well-posedness result in [10], which requires the initial velocity $u_0\in
H^2(\R^d)$ for the local well-posedness result, and a smallness condition on
the fluctuation of the initial density for the global well-posedness result.
