A system which undergoes shape change and produces contractile force in response to environmental stimuli is called a "chemomechanical system". This system transforming chemical free energy directly into mechanical work could serve as an "artificial muscle". In this paper, principle and chemomechanical behavior of slightly crosslinked poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) gel were discussed. The results obtained allowed us to conclude that the electrokinetic molecular assembly reaction of surfactant molecules on the polyelectrolyte network is responsible for this biomimetic movement of the gel.