In this paper, firstly, we consider the regularity of solutions in H i ([0, 1]) (i = 2, 4) to the 1D Navier-Stokes-Poisson equations with density-dependent viscosity and the initial density that is connected to vacuum with discontinuities, and the viscosity coefficient is proportional to ρ θ with 0 < θ < 1. Furthermore, we get the asymptotic behavior of the solutions when the viscosity coefficient is a constant. This is a continuation of [S.J. Ding, H.Y. Wen, L. Yao, C.J. Zhu, Global solutions to one-dimensional compressible Navier-StokesPoisson equations with density-dependent viscosity, J. Math. Phys. 50 (2009) 023101], where the existence and uniqueness of global weak solutions in H 1 ([0, 1]) for both cases:μ(ρ) = ρ θ , 0 < θ < 1 and μ = constant have been established.