Self-oscillating polymers and nano-gel particles consisting of N-isopropylacrylamide and the ruthenium catalyst of the Belousov-Zhabotinsky reaction have been prepared. In order to clarify the crosslinking effect on the self-oscillating behavior, the phase transition behaviors were investigated by measuring the transmittance and the fluorescence intensity of the polymer solution and the gel bead suspension. Cooperative effects due to crosslinking will play an important role for the design of nanoactuators.