RNA differential display reverse-transcripton PCR(DDRT-PCR) was applied to identify differentially expressed genes in Arbor Acres broiler(AA) and Beijing fatty chicken breast muscles in order to find the mechanism which induces the differential gene expression at the molecular level. A total of 7 ESTs were found using reverse Northern dot blot, and all of them were compared with the nucleotide sequences in GenBank database using BLAST. S1 was highly similar to HMGN3; S3 was highly similar to ChEST294a8 with unknown functions; S4 and S5 were highly similar to PGMⅠ; S6 and S2 had highly similar nucleotide sequences with unknown functions in nucleotide databases; S7 had no significant similarity with existing genes or ESTs and was regarded as a new EST. The new EST was submitted to GenBank(Accession number: EU594549). This lays a foundation for further study on the mechanism of differential gene expression in Beijing fatty and AA breast muscles.