Abstract: A connector connection structure of a junction box is provided. In this structure, junction box assembling and connector connecting can be performed at the same time. A rear cover which is slidable in the direction of connector engagement is temporarily engaged with the main body of the junction box. Connectors are engaged with connector housing, with the terminals of the connectors are unconnected to terminals of the substrate. When securing the main body to the bracket with a bolt, the rear cover is brought into contact with the bracket and moves in a relative direction of the connector engagement so as to connect the connector terminals to the substrate terminals. The main body is provided with a long slit having a tapered wall on which the head of the bolt slides to press the main body. Slide protrusions are formed on the main body, and guide slits having tapered portions are formed on the bracket.