Abstract: A method in the study of the mechanism of dimerization of acetylene by means of ~3H labelling was described. The proposed mechanism of dimerization of acetylene suggested by Chen Rongti et al. is described as follows. The results, which show that the count of the sample in catalytic system is two orders of magnitude greater than in the system without the eatalyst, demonstrate the presence of ~3H~+ and hence prove the possibility of the above suggested mechanism.