CCAST, World Lab, Beijing 100080, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100864, Peoples R China
; Jilin Univ, Dept Phys, Changchun 130021, Peoples R China
The nucleon spin structure function g(1) is studied based on a simple constituent quark model. Effects of low-lying nucleon resonances are discussed and the onset of Bloom-Gilman quark-hadron duality for the nucleon spin structure function is estimated. Our result qualitatively shows that in the range of Q(2)<0.75 GeV2, quark-hadron duality for g(1)(p) is violated.