The well-defined nonlinear multiresponsive, multihydrophilic block copolymers (MHBCs), poly(N-isopropylacrylamide)(2)-[poly(N-vinylpyrrolidone)-b-poly(acrylic acid)](2) ((PNIPAAM)(2)(PNVP-b-PAA)(2)) and poly[N-isopropylacrylamide-b-(acrylic acid)](2)-poly(N-vinylpyrrolidone)(2) (PNIPAAM-b-PAA)(2)(PNVP)(2)), were successfully synthesized via a combination of single-electron transfer living radical polymerization (SET-LRP) and reversible addition fragmentation chain transfer (RAFT) polymerization techniques. All the final miktoarm star block copolymers were characterized by GPC and H-1 NMR spectra. Interestingly, the hydrogen bonding interactions have a great effect on the water solubility of PAA chains, and the nonlinear MHBCs solutions showed sharp phase separation at pH = 7.0. The novel water-soluble nonlinear MHBCs consisting of pH-responsive PAA segments, thermoresponsive PNIPAAM segments, and hydrophilic, non-charged and biocompatible PNVP segments tend to self-assemble into three different types of micellar aggregates and tunimers, which can be reversibly controlled by pH value and temperature of aqueous solution of these copolymers.