The linkage structures between monomers make great influence on the properties of polymers.The synthesis of some special linkage structures can be challenging,which is often overcome by employing special reaction conditions.Here,we build dihydropentalene linkage in poly-naphthalocyanine on Ag(110) surface.Scanning tunneling microscopy (STM)and non-contact atomic force microscopy (nc-AFM) measurements confirm the dihydropentalene linkage structure and a possible formation path with reconstruction steps is proposed.The controlled experiment on Ag(100) surface shows no dihydropentalene structures formed,which indicates the grooved substrate is necessary for the reconstruction.This work provides insights into the surface restricted reactions that can yield special structures in organic polymers.