The present invention relates to novel 2,5-pyridinedicarboxylic acid derivatives and more particularly, to novel 2,5-pyridinedicarboxylic acid derivatives of formula (1) and its pharmaceutically acceptable salts as anti retroviral agents, having inhibitory activities against the proliferation of retrovirus such as hepatitis B virus and human immunodeficiency virus, including its preparing method, wherein, R1, R2, R3 and n are the same as defined in the detailed description of the invention, respectively.