Tests for effects of aspect ratio L/D on explosion characteristics of gasoline-air mixture in a closed tube were performed.The results showed that explosion pressure of gasoline-air mixture in an elongated closed tube rises in the form of two stages,the pressure rise rate curve presents a double-peak configuration; the maximum explosion pressure and the optimal gasoline-air concentration to get the maximum p_max value decrease gradually with increase in L/D ratio; the time to reach the maximum explosion pressure increases linearly with increase in L/D ratio,and the gasoline-air mixture near the optimal gasoline-air concentration is less affected by the aspect ratio L/D in comparison with those far from the optimal gasoline-air concentration; the second peak of pressure rise rate increases exponentially firstly and decreases in a negative exponential form after reaching the peak with increase in gasoline-air concentration; when the gasoline-air concentration is lower than the critical concentration,the second peak of pressure rise rate is lower than the first peak,while the result is the opposite when the gasoline-air concertration is higher than the critical concentration.All the first and second peaks of pressure rise rate and the gasoline-air concentration to get the maximum (d_p/d_t)max2 value decline with increase in L/D ratio.These conclusions provided a theoretical basis and an important reference for the explosion proof design of pipelines.