Poly(vinyl chloride) (PVC)/bis(2-ethylhexyl)phthalate (DOP) gels were prepared at room temperature from tetrahydrofuran solutions of PVC and DOP. PVC/DOP gels of different molecular weights at various PVC concentrations (c) were investigated with small-angle X-ray scattering (SAXS). The mean distance between two neighboring inhomogeneities (D) and two characteristic lengths, the intrainhomogencity distance (d(1)) and interinhomogeneity distance (d(2)), were evaluated from Bragg's law and the distance distribution function, respectively, Both D and d(2) can be expressed by a power-law relation (e.g., D and d(2) proportional to c(-0.5)). After a period of rapid cooling to 25 degreesC from the sol state, the structural evolution was examined with time-resolved SAYS measurements. An Avrami analysis with the SAXS invariant data revealed that the growth kinetics of PVC/DOP gels was one-dimensional growth from predetermined nuclei, regardless of c. These results suggest that the PVC/DOP gels are constructed from a fibrillar structure that forms gel structures at high concentrations or low temperatures.