A terminal connection structure of a battery is disclosed. A terminal connection structure of the battery is for electrically connecting positive and negative terminals of battery modules of a first row and battery modules of a second row that is adjacent to the first row in a plurality of rows where battery modules are arranged. The terminal connection structure of the battery may include: a first bus bar module electrically connecting the positive and negative terminals in the first row of battery modules; and a second bus bar module configured to electrically connected to the positive and negative terminals in the battery modules of the second row, stacked vertically on the first bus bar module, to be electrically connected to the first bus bar module.