The changes of cloud points and surface tensions of a nonionic surfactant dodecyl polyoxycthylene(5) polyoxypropylene(4) ether (LS54) in aqueous solutions with added polyvinylpyrrolide (PVP-K90) were determined in order to evaluate polymer-surfactant interactions in the bulk solutions. A new model, corona-shaped intra-chain micelles, was applied lo these phenomena and the thermodynamic parameters of micellization were determined.