We developed "self-oscillating" polymer gels that undergo spontaneous cyclic swelling–deswelling changes without any on–off switching of external stimuli, as with heart muscle. The self-oscillating gels were designed by utilizing the Belousov-Zhabotinsky (BZ) reaction as oscillating reaction. We have systematically studied these self-oscillating polymer gels since they were first reported in 1996. Potential applications of the self-oscillating polymers and gels include several kinds of functional material systems such as biomimetic actuators, mass transport systems and functional fluids. For example, it was demonstrated that an object was autonomously transported in the tubular self-oscillating gel by the peristaltic pumping motion similar to an intestine. Further, self-oscillating polymer brush surface like cilia, vesicles or colloidosomes undergoing cell-like autonomous shape oscillations with buckling, was prepared. Besides, autonomous sol-gel oscillation and amoeba-like motion was realized utilizing well-designed block copolymer solution. In this talk, our recent progress on the self-oscillating polymer gels is summarized.