Sequence-controlled oligomers of cyclic imino ethers were synthesized by the one-pot multi-stage feeding method. Selective formation of the sequence was clearly demonstrated by equimolar reactions between the monomers and 1:1 adducts of an initiator with the monomers. Efficiency of the sequence control is determined by the difference of reactivities of the active ends. A new general prerequisite to synthesize a well-defined sequence by multi-stage oligomerization was proposed.