A joint connector block, which easily meets a demand of a complicated and highly dense joint circuit, is provided. It includes: a block body 2 having a plurality of connector-fitting chambers 7 arranged in a line on one side of the block body and a busbar-receiving part 2b communicating with the connector-fitting chambers on an opposite side of the block body; a plurality of longitudinal busbars 3, each of which includes at least one branch terminal 24 projecting in the connector-fitting chamber and at least one pair of clip terminals 23 situated on the side of the busbar-receiving part; and a plurality of lateral busbars 4, each of which includes at least one branch terminal 26 projecting in the connector-fitting chamber and a connecting part 25 to be connected to the pair of the clip terminals 23 on the side of the busbar-receiving part, the lateral busbar being connected to the longitudinal busbar crossing the longitudinal busbar at right angles.