Belousov-Zhabotinsky (BZ) reaction-induced mechanical oscillation of poly(N-isopropylacrylamide) (PNIPAM) gel particles was investigated by the systematic variation of BZ substrate concentrations. The correlation between the dynamic behavior and substrate concentrations was presented in a ternary phase diagram. Both oscillatory and steady-state regimes exist on the phase diagram and are separated by a high-frequency oscillation band. Dependence of oscillation frequency and induction time on the substrate concentrations was also studied. To achieve size uniformity, these PNIPAM gel particles with covalently bound tris(bipyridyl)ruthenium(II) were synthesized via the coordination chemistry between a ruthenium complex and the monodispersed PNIPAM gel particles bearing bipyridine ligands.