— One of features of soft object manipulation is motion during deformation of the soft body. We analyze the stability of soft object manipulation by simultaneous control of motion and deformation. We model and formulate manipulation by simultaneous control of the motion and deformation of soft object. We then use the symmetric linear mass-damperspring model for a simple analysis of its dynamical behavior. Second, we analyze the stability of the system. Thus, we show that an adequate feedback gain stabilized the system in PID control. This adequate feedback gain ranges between two positive values. The object cannot be stably controlled at too high a gain; neither can, it be regulated at too low a gain since the object is movable. Furthermore, we unravel the features of soft object manipulation by simultaneous control of motion and deformation.