In-plane aligned c-axis oriented YbBa 2Cu 3O 7− δ (Yb123) films were successfully prepared on SrTiO 3 substrates by chemical solution deposition (CSD) using metal naphthenates under low oxygen partial pressure. The homogeneously coated films on SrTiO 3(100) were calcined by different heat-treatment profiles to decompose their organic components. These calcined films were fired at 750°C under 10 −4 atm of oxygen partial pressure (pO 2). The microstructures and the superconducting properties of the final Yb123 films are highly dependent on the heat-treatment profiles of calcination to obtain a uniform amorphous state. It has been confirmed by transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) measurements that the heat-treatment of rapid heating and quenching is effective to prepare good calcined precursor film.