Tucidinostat, a novel histone deacetylase inhibitor has been approved for the treatment of relapsed or refractory peripheral T-cell lymphoma in China. Azacytidine is a hypomethylating agent. The aim of this study is to compare the efficacy and safety of azacytidine, tucidinostat combined with CHOP regimen and classical CHOP regimen in the treatment of primary PTCL