The possibility of applying the models of the irreversible aggregation and the fractal analysis for the description of curing kinetics of haloid-containing epoxy polymers was shown. There are two different modes of curing (homogeneous and nonhomogeneous), responding to conditions D = const and D = variant as a function of reaction time (D is the fractal dimension of microgels). The first condition corresponds to one dimension of the formed microgels, and the second one corresponds to the distribution of these dimensions. The mode of curing is determined by the level of fluctuations of density in the reaction medium. It was also shown that the fractal reactions at curing can be of the two following classes: reactions of fractal objects and reactions in fractal space. The basic difference of the two mentioned classes of reactions is the dependence of their rate on the fractal dimension of reaction products. The application of the methods of the fractal analysis and the theory of percolation allows us to find out that the first gelation point by crosslinking polymers is a structural transition, which is realized at filling by microgels of the whole reaction space. The physical nature of the autoacceleration (autostopping) effect in curing reactions is determined. (C) 2004 Wiley Periodicals, Inc.