  An unified scheme for describing both spin and orbital motion in
symmetry-breaking chiral quark model is suggested. The analytic results of the
spin and orbital angular momenta carried by different quark flavors in the
nucleon are given. The quark spin reduction due to spin-flip in the chiral
splitting processes is compensated by the increase of the orbital angular
momentum carried by the quarks and antiquarks. The sum of both spin and orbital
angular momenta in the nucleon is 1/2, if the gluons and other degrees of
freedom are neglected. The same conclusion holds for other octet and decuplet
baryons. Possible modification and application are briefly discussed.
