To provide an exhaust gas passage structure for an engine capable of improving warming-up performance of the engine by efficiently rising cooling water temperature and oil temperature with effectively using waste heat of exhaust gas in a re-circulation passage when the engine is cold.

The re-circulation passage 15 re-circulating part of exhaust gas discharged to the exhaust gas passage 13 from a combustion chamber of the engine 1 to an intake air passage 14 is provided. The part of the exhaust gas flowing in the re-circulation passage is cooled by a cooling device 4. A bypass passage 16 is provided between a downstream side of the cooler device of the re-circulation passage and the exhaust gas passage in a downstream of the re-circulation passage. An open and close valve 17 opening when the engine is cold is provided in the bypass passage. The part of the exhaust gas discharged to the exhaust gas passage from the combustion chamber when the engine is cold is positively circulated in the bypass passage from the re-circulation passage to heat oil and cooling water flowing ion the cooler device.