A microcomputer-controlled N2 gas laser photolysis system has been used to elucidate the dynamic behavior in the excited state of poly(N-vinylcarbazole), poly[2-(9-carbazolyl)ethyl vinyl ether] and polyurethanes having trans-1, 2-di(9-carbazolyl)cyclobutane in N, N-dimethyl-formamide. Under the stringent optical arrangements, the excitation intensity dependences of the transmitted intensity of the exciting pulse, the fluorescence intensity and the Tn←Tt absorbance were investigated, which were interpreted in terms of the intrapolymer S1-S1 annihilation. On the basis of these results, the relation between the S1-S1 annihilation and polymer structure was examined and the states formed through the S1-S1 annihilation were proposed to be the ground and triplet states of carbazolyl chromophores. This S1-S1 annihilation was directly observed with a ps Nd3+: YAG laser-streak camera system. By the analysis of the results of ps studies, the mean rate of energy migration from chromophore to chromophore was estimated to be 1012 s-1. The results of the present work have been found to be useful for elucidating the laser-induced primary photoprocesses of polymers.