Strong modulation between crystal symmetry and the corresponding RuO₆ octahedral configurations were verified by structural model calculations based on the diffraction data of 20 individual half-order peaks. This proves that the compressively strained SrRuO₃ thin film has pseudo-orthorhombic (monoclinic, P21/m, #11) structure with the BO6 configuration of a⁺a^–c^– at 25 °C and tetragonal (I4/mcm, #140) with the octahedral tilt of a⁰a⁰c^– above 285 °C. The structural phase transition from pseudo-orthorhombic to the tetragonal structure was determined at around 285 °C and epitaxial strain was persistent during the structural phase transition in the fully strained SrRuO₃/SrTiO₃ heterostructured thin film.