Dyes are colored organic compounds that are used to pigment fiber or other materials. Dyes are mainly calssified into natural and synthetic dyes in terms of the origin. Natural dyes include animal dyes, plant dyes and mineral dyes with such defects as incomplete chromatogram, inconvenient use and color fading, and thus have been gradually eliminated. In 1856, the 18-year-old young British scientist Perkin successfully invented the world's first synthetic dyes. He built his own factory and industrialized synthetic dye production. Over 100 years since then, dye industry has undergone rapid development, and by 2001 synthetic dyes already have been up to nearly 10,000 varieties. In 2004, the output of total dyes in the world has reached 900,000 tons. Synthetic dyes are used comprehensively, not only to dye synthetic fibers, but also natural fibesr, fur, leather and man-made fibers.