Based on the magnetic atomic guidance model proposed in our previous paper [Opt. Commun. 160(1999)72],the quantum motion of atoms in a magnetic tube is discussed in detail. The non-adiabatic loss of atoms as resultof spin-flip transition and the adiabatic condition for keeping atoms in the guidable state are also analysed. Theresult shows that the atoms can be guided in the magnetic waveguide with a higher guiding efficiency by choosingsuitable parameters of the magnetic tube.