In order to clone cDNAs coding for proteins specially-binding to NF-IL6's 3'UTR, a phagemid expression library was constructed from cDNAs of revertant RR cells. The termination codons of those cloned cDNAs were largely removed by restricted exo III enzyme digestion, in order to facilitate the expression of cDNA as fusion proteins with the phage gene III. Examinations of this library showed that the library includes various lengths of cDNA inserts and it can express exogenous cDNA.