  Magneto-resistance (MR) of Bi$_2$Se$_3$ nanoribbons is studied over a broad
range of temperature ($T$=300K-2K) and under various magnetic field ($B$)
orientations. The MR is strongly anisotropic with the perpendicular MR much
larger than the longitudinal and transverse MRs. The perpendicular MR exhibits
quadratic $B$-dependence in low fields and becomes linear at high $B$. However,
when $T$ increases, the perpendicular MR becomes linear over the whole magnetic
field range (0-9T) up to room temperature. This unusual linear MR is discussed
in the context of the linear quantum MR of the topological surface-states. We
also observe the boundary-scattering effect in MR at low temperatures, which
indicates that the out-of-plane Fermi momentum is much smaller the in-plane
Fermi momentum, excluding the simple three-dimensional Fermi surface picture.
