An in-situ mineralization process in the presence of thermo-responsive microgels leads to the formation of well-defined hybrid materials. Experimental data suggest the control of mineralization process in the presence of the microgels offers a possibility to obtain sub-micrometer particles or macroscopic hybrid hydrogels. the rapid formation of CaCO3 crystals in the microgel structure favors the preparation of the hybrid particles wherein inorganic crystals cover the shell layer of the microgel. The slow formation of CaCO3 crystals leads to the simultaneous self-assembly of the microgel particles on the bottom of the reaction vessel, and the formation of a physical network. It has been demonstrated that the hybrid hydrogel materials with different calcium carbonate contents and temperature-dependent swelling-deswelling properties can be prepared.