The present invention provides ionomer-type emissive polymer whose heat-stability is improved by the formation of ionic cross-link, and electroluminescent device employing the same as an emissive layer. The ionomer-type emissive polymer is characterized by an ionomeric conformation, which has a backbone in a conjugate, non-conjugate or conjugate/non-conjugate multi-block conformation with or without a side chain in a conjugate or non-conjugate conformation, and 0.1 to 15% (mol/mol) of ions bound to the backbone or side chain of the emissive polymer with or without linker. The electroluminescent diode employing ionomer-type emissive polymer can be applied to the preparation of long-life and electricity-saving electroluminescent display device since it can luminesce at low voltage due to its ionomeric conformation and have higher heat-stability than the conventional ones.