We obtained the shear viscosity 7 and optical probe (67-nm polystyrene latex spheres) diffusion coefficient D in hydroxypropylcellulose (HPC)/water at temperatures T = 10,25, and 39 O C . Polymer samples had weight-average molar masses M of 139,146,415, and 1280 ma. Polymer Concentrations c ranged up to 40-100 g/L; 7 was as large as 1@-1@ CP in different systems. 7 has a stretched-experimental dependence on c at small c and power-law behavior at large c. D generally follows a stretched exponential DO exp(-ac') but is consistent with power-law behavior at large c. Individual spectra fit well to Williams-Watta forms A0 exp(-Ote). The dependence of a, v, 0, and @ on c, M, and Tis discussed.