Dielectric measurements were carried out on blends composed of poly(n-butyl acrylate) (PBA) and poly(propylene glycol) (PPG) exhibiting phase behavior of the UCST type. Both linear PPG and three-arm star-shaped PPG were used. The frequency dependence curves of the dielectric loss factor is an element of'' exhibited a main peak due to segmental motions and a shoulder due to the normal mode relaxation of the PPG molecules. Depending on the difference between the cloud point T-cloud and temperatures of dielectric measurements T-meas, the shape of the is an element of'' curves changed. The observed is an element of'' curves were compared with theoretical is an element of" curves calculated on the basis of mixing rules for the completely mixed and demixed states. It was found that when T-meas similar to T-cloud, the is an element of" curves exhibited relaxation spectra intermediate to the theoretical curves for the mixed and demixed states. This indicates that the PEA and PPG segments are not perfectly mixed even at temperatures above the cloud point. The main peak was broader than those of the components, but the peak for the normal mode did not exhibit broadening, indicating that the correlation length of the heterogeneity is less than the end-to-end distance of the PPG molecules. A Gaussian distribution of the local concentration can be deduced from the is an element of" curves. Dielectric behavior of blends containing star-shaped PPG was found to be similar to those with linear PPG.