an open - close portion structure of a vehicle body includes : an open - close member which opens and closes an opening of the vehicle body ; a first hinge member provided on the vehicle body ; a second hinge member provided on the open - close member , being pivoted with the first hinge member ; and a stretchable stay provided between the vehicle body and the open - close member and biasing the open - close member to open , wherein an end of the stretchable stay is coupled to the second hinge member .