To provide a complex of an in vivo stable polymer and a double- stranded polynucleotide having high ability to bind to human SLE anti-dsDNA autoantibody.

This complex is a chemically defined complex of an in vivo stable polymer such as a copolymer of D-glutamic acid and D-lysine and a double-stranded polynucleotide having at least about 20 base pairs and the complex has high ability to bind to anti-dsDNA autoantibody. The double-strand preferably has uniform length and structure and binds to a polymer by reaction of one functional group reactive to amino group with an amino group at one of the end or near the end of each double-strand. These complexes are tolerogens to human systemic lupus erythematousus.