In this study, we challenged to derive new piezoelectric materials with biocompatibility by first principles calculation. Firstly, constituent elements of biocompatible piezoelectric materials have been specified by HSAB method from the viewpoint of interaction energy with in-vivo molecules. Secondly, in order to create a perovskite-type crystal structure with good piezoelectric response, the combination of biocompatible elements was selected to satisfy geometric stable condition defined by tolerance factor. Then, we focused on silicon oxides and investigated on phonon vibration mode at paraelectric phase of cubic structure and piezoelectric response at ferroelectric phase of tetragonal structure.