The present invention provides a joint construction in an upper part of a center pillar, in which a groove part 5 having a substantially U-shaped cross section, which is open upward and extends in the longitudinal direction of a vehicle 1, is provided in a joint portion between a roof panel 2 and a side body outer panel 3 of the vehicle 1, wherein a roof center member 6 is provided under the roof panel 2, and on the other hand, a rail side inner panel 12 and a center pillar reinforce 10 are provided in a center pillar upper portion D; a vehicle inside end part 10a of the center pillar reinforce 10 extends toward the upper inside of the vehicle 1, and is joined to the roof center member 6, the roof panel 2, and the side body outer panel 3 in the groove part 5; and the vehicle inside end part 10a of the center pillar reinforce 10 is provided so as to extend to a vehicle inside end portion 12a of the rail side inner panel 12.