The response of VLFS in waves is a typical hydroelastic problem. Because the horizontal scale of box-typed VLFS is much larger than its vertical scale, the bending rigidity of the structure is relatively very small, the elastic deformation of floating bodies and the coupling between structure and fluid must be considered. Thus it should be necessary to employ hydroelastic theory to solve the response problems.Due to the very large scale of these structures and corresponding strict experiment conditions, lots of difficulties would exist in the experimental research. Therefore, in view of economical efficiency, reliability and implementation etc, theoretical research on the hydroelastic problems of VLFS would be of importance. The main research contents in this dissertation are as follows:Within the framework of linear theory, the hydroelastic behaviors of a floating plate in waves on a fluid of finite depth are investigated. A feature of the corresponding boundary value problem is the high order of the derivative in one of the boundary conditions and the additional conditions at the plate edge. The Weiner-Hopf technique has many merits in solving the hybrid boundary value problems. By the aid of the Wiener-Hopf technique, some analytic solutions of the diffraction of surface wave by an elastic floating plate can be readily constructed and it is necessary to extend the solution to the entire complex plane. Then two constants appear that must be determined from the conditions at the edges. Since the effects of the transverse shearing and moments of inertia is considered in the theory of Mindlin thick plates, the results obtained are much more close to the practical cases than the results by the classical theory of thin plates or Euler beam for small shear modulus materials. In this paper, the analytic solutions of the hydroelastic problems of VLFS are constructed based on above theories and methods. At the same time, the effect of the floating plate's thickness on the hydroelastic response is analyzed.The influence of water depth on the hydroelastic response of a very large floating platform of finite length is investigated. Firstly, based on the dynamical theories of water waves and Mindlin thick plates, the hydroelastic response of a two-dimensional very large floating plate to plane incident wave is investigated for the case of infinite water depth. The system of linear algebraic equations, which contain six equations, is deduced and the expressions of the reflection and transmission coefficients are obtained. For the cases of different water depth, the hydroelastic response of VLFS against several kinds of incident wave is investigated. The influence laws of water depth on the hydroelastic response of floating plates are obtained by comparing the results with the case of infinite water depth.The hydroelastic behaviours of an elastic plate of finite length floating on the free surface of a liquid under the action of a periodic external load are analyzed. When the power equipments or other exciting sources are located on VLFS, these motivation acted on VLFS would impact the security and reliability of VLFS. Thus it is necessary to investigate the hydroelastic behaviours of VLFS under the action of these exciting sources. In the paper, based on the dynamical theories of Mindlin thick plates and the Wiener-Hopf technique, the planar problem of the unsteady behaviour of an elastic plate of finite length floating on finite water depth is investigated in the case of different periodic external loads (i.e. point load and distributed load). In addition, the relationship of the amplitude distribution of the deflection with the acted centre and wide of the excited load with different periods are analyzed.The investigation of the wave-induced responses of an elastic floating plate with elastic edge-restraint in water waves is presented. By far, many theoretic and experimental researches on the mooring system of VLFS had been made, the anchor chains of the mooring system had rarely been regarded as elastic body in analyzing the hydroelastic behaviours of VLFS by few researchers. Based on above reasons, the anchor chains, which are used to connect the sea bottom and the floating plate's edge, are regarded as springs in analyzing the hydroelastic behaviours of VLFS in the paper. The relations between the spring stiffness and the parameters of wave-induced responses of floating plates are analyzed and the merits and faults of several edge-restraint cases are indicated by comparison. Therefore, these results can be used as theoretical bases at the design stage of super floating platform systems.