<正> The fluorescence behaviours of a new polymer poly [oxy-2 （4-N, N-dimethylaminobenzyl） propane-1 , 3-diyloxy-terephthaloyl] （Ⅰ） in solution were studied. Inter-and intra -molecular exciplex is formed between the singlet excited state of N, N- dimethylanilino group （abbreviated to DMA） and the ground state of terephthalate group （abbreviated to TP）. The intensity ratio of the long wavelength exciplex fluorescence to the short wavelength emission of DMA group is used as an index for the inter-and intra-molecular interaction of chromophores. The results are compared with model polymer polyoxy-2-（4-N ,N-dimethylaminobenzyl） propanc-1 , 3-diyloxyadipoyl （Ⅱ）, model monomer compound 4-N, N-dimethylaminobenzylmethyl terephthalate（Ⅲ） and diethyl 2-（ 4-N, N-dimethylaminobenzyl） malonate （Ⅳ）. Polymer association derived by electron donor and acceptor interaction （EDA） is further verified as a key role in the interpolymer exciplex formation . The fluorescence decay time of （Ⅰ） and monomer （Ⅲ） are measured in solutions.