Myocardial cells are terminally differentiated and have no ability to regenerate.Apoptosis is the main mechanism for myocardial cell loss and can cause heart failure or other serious consequences.Mammalian myocardial cells have been intensively studied;however, few studies have explored chicken myocardial cells and the apoptosis pathways in these cells are unclear and some key apoptosis genes are still unknown.To investigate these issues, primary cultures of embryonic chicken cardiomyocytes were maintained and treated with hydrogen peroxide to induce cell apoptosis.RNA was then extracted and RNA sequencing was performed to determine differential gene expression,identify novel transcripts and to construct a protein-protein interaction network.After sequencing, 19,268 known genes and 2,160 novel genes were investigated.Differential gene expression analysis identified 4 650 genes that showed significant differential expression between the apoptosis-induced and control groups.Among them, 10.4% were up-regulated while 18.9% were down-regulated.In response to apoptosis induced by hydrogen peroxide, apoptosis initiation was mainly dependent on caspase-8,9, which activated caspase-3 and caspase-6.The signaling pathway is very similar to the mammalian myocardial cell apoptosis pathway.