Restructuring mechanisms of soot particles that are in an atmosphere of a condensed vapor are considered. It is found that the condensation of vapor on a surface of previously rarefied soot aggregates leads to the formation of compact fragments of close-packed particles-globules. The effect of water vapor is established to depend on the charge and chemical composition of the particles. It is shown that the effect of vapor manifests itself first and foremost in a fractal dimension change and in the shift of the particle size distribution to the range of small sizes. In the context of the theory of fractal systems, a model that accounts for the influence of capillary forces on restructuring processes of soot clusters is proposed.