On-surface fabrication of covalently interlinked conjugated nanostructures has attracted significant attentions mainly due to their high stability and efficient electron transportability. Here, from the interplay of scanning tunneling microscopy imaging and density functional theory calculations we have for the first time reported on-surface formation of one-dimensional polyphenylene chains through Bergman cyclization followed by radical polymerization on Cu(110). The formed surface nanostructures are further corroborated by the results of the ex-situ synthesized molecular product after Bergman cyclization. These findings are of particular interest and importance to the construction of molecular electronic nanodevices on surfaces.