This book contains synthesis and characterization of thermo responsive poly(N-isopropylacrylamide) pure and hybrid microgels with different cross-linker contents.The hybrid microgels obtained by the introduction of silver nanoparticles in pure microgels. The prepared samples were than analyzed by using FT-IR, Dynamic Laser light Scattering (DLS) and UV/Visible spectroscopic techniques.With increasing cross-linker contents the size of particles reduces.