The joined- wing is an innovative aircraft configuration with a structural connection between the front wing and the rear wing. An approach was presented to investigate the dependences of the structural weight of a hign-aspect-ratio joined-wing on the parameters of its aerodynamic configurations. Such thedependences are essential for the priliminary deisgn of the joined-wing configuration. The approach consists of two steps. The first step is that the joined-wing structural weights were predicated by the combination of parameterized modeling of the finite element method (FEM) with structure optimization method. The second step is that the quantitative relationships between joined-wing configuration parameters and structural weights were explored using the design of experiment (DOE) method and response surfaces model. Based on this approach, the dependences of the wing structural weight of the joined-wing on the configuration parameters were obtained, which indude the span of front wing, the ratio between front wing span and rear wing span, the aspect ratio of front wing, the dihedral of front wing, the sweep of front wing, the longitudinal distance between front and rear wing, and the vertical distance between front and rear wing. The dependences obtained can be used as a guidance for the preliminary sizing of the high-aspect-ratio joined-wing configurations.