Inherent viscosities were measured for poly(ethylene oxide) (PEG) in tetrahydrofuran/water (THF/WT). The measured temperature range covered the range from 35 degrees C close to the lower critical solution temperature T-c of THF/WT system. It was found that near the critical temperature, the inherent viscosities contract down to about one-third of the value at 35 degrees C. The overall contraction behavior agrees well with de Gennes’ theory, but two observations contradict his prediction. First, the reduced Theta temperature, tau(Theta), at which the unperturbed chain dimension is observed strongly depends on the molecular weight. Second, we observed only the contraction behavior instead of the contraction-and-reswelling on approaching close to the critical point. The expansion factors alpha(eta)(3)(=[eta]/[eta](Theta)) for the different molecular weight samples fall on one master curve when plotted as a function of [log tau - log tau(Theta)] M-w(1/2). Here tau(=(T-c - T)/T-c) and M-w are the reduced temperature and the weight-average molecular weight, respectively.