To efficiently disperse fibers at a high speed and add the dispersed fibers to an asphalt when mixing the fibers in a vegetable fiber-mixed asphalt.

This system has a structure for making vegetable fibers collide with barrier valves 3 in a pipe 1 under a wind pressure of high-pressure air by a fan 2 and dispersing the vegetable fibers. The barrier valves 3 are continuously attached to the upper and lower sides in the pipe 1. The vegetable fibers repeating the collision are then gradually dispersed. Furthermore, the high- pressure air plays a role in delivery to an asphalt plant and addition to the asphalt and bears a series of operations.