Provided is an optical transmission line in which the suppression of SBS and the achievement of other transmission characteristics can compatibly be attained. The optical transmission line is formed by connecting a first optical fiber and a second optical fiber, or by connecting a group of first optical fibers and a group of second optical fibers, in which the difference in Brillouin frequency shift therebetween is 200 MHz or more. In at least one of the first optical fiber and the second optical fiber, the transmission loss may be 0.32 dB/km or less at a wavelength of 1383 nm. In each of the first and second optical fibers, the mode field diameter may be not less than 8.2 .mu.m and not more than 9.8 .mu.m, the cable cutoff wavelength may be equal to or less than 1260 nm, and the zero dispersion wavelength may be not less than 1300 nm and not more than 1324 nm. The difference between the average Brillouin frequency shift of each optical fiber group and the Brillouin frequency shift of each optical fiber contained in the respective optical fiber group may be equal to or less than 40 MHz.