This study presents a forming configuration being an original three-dimensional geometrical model of forming dough pieces into spherical forms. Based on the forming configuration, the description of motion for a formed dough piece was made according to the principles of motion of a rigid body. Kinematic relationships concerning the dough piece material as a rheological fluid were formulated in accordance with the laws of fluid mechanics. Next, the relationships between the kinematic quantities present in both descriptions were defined. Presented in the assumed forming configuration (spherical coordinate system), the components of the deformation velocity tensor describe the velocity distribution over the surface of the formed and deformed dough piece. Determined kinematic quantities, as well as the relationships defined between them, describe the kinematics of forming dough pieces, and can be used to provide a dynamic description of the process of fanning dough pieces into spherical forms.