One-dimensional valence bond solid (VBS) states represent the simplest symmetry protected topological phases.We show that their ground state entanglement spectrum contains both topological and non-topological structures.For the SO(3) symmetric VBS states with odd-integer spins, the two-fold topological degeneracy is associated with an underlying Z_2xZ_2 symmetry that protects the corresponding topological phase.In general, for the SO(2S+1) symmetric VBS states with integer spins S, the corresponding protecting symmetry is identified as the (Z_2xZ_2)^S symmetry, yielding the 2^S-fold topological degeneracy.The topological degeneracy and associated protecting symmetry can be identified by a non-local unitary transformation, which changes the topological order of the VBS states into conventional ferromagnetic order.