In this work, we provide on atomic-scale the details of the interfaces and domain walls in PZT/SRO heterostructure films by means of aberration-corrected high resolution electron microscopies. The negative Cs imaging (NCSI) technique based on aberration-corrected transmission electron microscopy (TEM) combined with high-angle annular dark field (HAADF) imaging and annular bright field (ABF) imaging based on scanning transmission electron microscopy (STEM) allows us to determine the chemical information and the full structural arrangement including chemical elements with a low atomic number such as oxygen at the heterointerfaces and the structure of 180° domain walls within ferroelectric PZT films.