The results of studies on the cyclotrimerization process of 1,3-butadiene to 1,5,9-cyclododecatriene in the Et3Al2Cl3/TiCl4 catalytic system in the toluene medium have been presented. On the basis of preliminary experiments of this process it was found that the molar ratio of Et3Al2Cl3:Ti (X (1)) in the range of 2-20, the TiCl4 concentration (X (2)) in the range of 2-20 mmol/dm(3), and temperature (X (3)) in the range 40-80 A degrees C have a significant influence on the 1,5,9-cyclododecatriene synthesis. In order to achieve the complete description of process, the statistical experimental design methods were utilized because they allows to obtain the mathematical model combining the characteristic magnitudes of process in the form of functional relationship. As a response function (objective function) was selected the selectivity of transformation to 1,5,9-cyclododecatriene in relation to consumed 1,3-butadiene (S (CDT/BD) ). It was found that the largest influence on the value of S (CDT/BD) has the molar ratio of Et3Al2Cl3:Ti and temperature. Over the studied range of variation of independent factors, an increase in the Et3Al2Cl3:Ti molar ratio, the TiCl4 concentration, and temperature causes initially the increase of S (CDT/BD) to the maximum value, and subsequently its decline. The maximal selectivity of 1,5,9-cyclododecatriene formation (S (CDT/BD MAX) = 100 mol%) was achieved at the molar ratio of EASC:Ti X (1) = 14.8, the TiCl4 concentration X (2) = 12.7 mmol/dm(3), and at a temperature X (3) = 54.6 A degrees C.