A vehicle exhaust system structure capable of easily improving output performance in comparison with a two-cylinder internal combustion engine having the same displacement and outputting an appealing and excellent exhaust sound relating to the two-cylinder internal combustion engine, in a four-cylinder internal combustion engine or a three-cylinder internal combustion engine. An exhaust pipe structure for an internal combustion engine is configured such that exhaust pipes are respectively connected to four cylinders of a four-cylinder internal combustion engine, the two exhaust pipes of the exhaust pipes are formed as long exhaust pipes having a long pipe length while the other two exhaust pipes thereof are formed as short exhaust pipes having a short pipe length, and a difference in a pipe length between the long exhaust pipes and the short exhaust pipes is set to 150 mm or more.