Abstract: In a chain V-belt working on a pair of two-split pulley blocks and having a plurality of links coupled endlessly therefor, a projection is formed on the inside of the links when the belt is coupled endlessly, a block slender in section to be long perpendicular of the direction in which the belt runs and short in the direction in which the belt runs is installed on the projection so as to engage with the pulley blocks through both ends of the block, a slip between the belt and the pulley blocks is prevented to transmit a power securely, the belt is made to run stably even at the time of transmission, a large power is transmitted on a small surface pressure.