∵z=- 1 2 + 3 2 i，∴z2＝(? 1 2 + 3 2 i)2=? 1 2 ? 3 2 i，∴z3=z2?z=(? 1 2 ? 3 2 i)(? 1 2 + 3 2 i)=(? 1 2 )2+( 3 2 )2=1．故选：A．
