A wavelength division multiplexing optical fiber transmission line that reduces signal deterioration caused by dispersion even in a transmission system having a high-speed transmission rate, and is suited to a long-distance transmission. A dispersion management transmission line is connected between optical repeaters. The dispersion management transmission line has 3 to 6 pairs of fiber sections, of which each has a positive dispersion fiber and a negative dispersion fiber, connected in series. Dispersion compensation is made step by step over four (4) times for dispersion and a dispersive slope, which were accumulated by the front-stage positive dispersion fiber, by the next-stage negative dispersion fiber.