The main objective of the project is to develop the high fastness fluorescent solution dyed yarn. After polymer compounding, we can modify the fluorescent colorant. The particle size of fluorescent colorant is under190 nm, and the colorant content is 20 to 30wt% of color master-batch. The development high fastness fluorescent solution dyed yarn technology can not only be applied to high-visibility clothing but also complying with EN471 specifications.