Abstract. Let K=Q be an abelian extension containing an imaginary qua-
dratic ¯eld k. Each intermediate ¯eld of the cyclotomic Zp-extension of K
contains both the group of elliptic units and the group of circular units. We
explain the relation between the characteristic ideals of the inverse limit of the
minus ideal class groups and the inverse limit of the quotients of the circular
units by the elliptic units using the Iwasawa main conjectures.