  The object of this brief review is to reconcile different points of view on
how the spin of proton is made up from its constituents. On the basis of naive
quark model with flavour symmetry such as isospin or SU(3) one finds a static
description. On the contrary the local SU(3) colour symmetry gives a dynamical
view. Both these views are contrasted and the role of U(1) axial anomaly and
the ambiguity for the measurable spin content is discussed.
