This review article presents results of investigations concerning the kinetics of crosslinking photopolymerizations. The main emphasis is given to the propagation and termination rate coefficients and to the determination of the mechanism of the termination process. To emphasize the special features of the kinetics of the photocrosslinking process, a comparison with the kinetics of linear polymerizations has been made. Moreover, the paper describes the influence of various factors, both chemical as well as physical (e.g. monomer, structure, system composition, oxygen, temperature) on the chemistry of network formation. The effects of amino, ether and sulfide groups present in additives or introduced within monomer molecules are also discussed.