A negative-pressure smoke-guiding fireproof building structure includes at least one vertical smoke discharge flue arranged in the building and in fluid communication with a transverse smoke discharge flue arranged in upper space of each floor. At least one natural air inlet window having a door and at least one smoke-gas discharge window having a door are arranged in a wall of each independent room off each floor. The doors normally seal the windows in a closed position and are capable of automatically opening at a fire hazard. The smoke-gas discharge window is in fluid communication with the transverse smoke discharge flue. With a simple structure, the building structure effectively prevents fire spreading to peripheral adjacent rooms when one room in the building catches fire, so as to prevent a larger fire hazard.