Alginate (SA) and chitosan (CS), including numerous cationic and anionic groups, are naturally occurring biopolymers that are being applied to the biotechnology industry. The possibility as actuator and biosensor of the SA and CS films was investigated in the electric stimulus. Electric sensitivity and reversible bending behaviors were measured in the electrolyte solution with varying ionic strength. The electroresponsibility was measured by bending behavior method. The response rate (degree/sec) was increased with the increment of the applied voltage and indicated the maximum value at ionic strength 0.1 M. The measured results showed the possibility as actuators and biosensors in the electric stimuli.