Regularities of the dicyclopentadiene cationic oligomerization under influence of the catalytic system AlEt2Cl: TiCl4 in toluene solution were studied. The most probable mechanism of polymerization in this system is the propagation chain on the contact or solvate-separated ion pairs. The effective rate constant of solvation of the catalyst and chain propagation were calculated. The thermal oligomerization effect and heat of the catalyst system components solvation are determined by heat of oligomerization raw material containing dicyclopentadiene. When taking into account the data of both material and thermal balance the experimental data were described adequately.