Wave energy is one of promising renewable energy for power generation, and linear generator is suitable for wave energy capture. While it faces some problems, such as seawater corrosion and inconvenience maintenance. This paper promotes a fully floating system for wave energy converter with direct-driven linear generator to surmount this shortage. The dynamic characteristic of the system is investigated using theoretical analysis by coupling the dynamics of the wave with sinusoid assumption, as well as the performance of the linear generator. The results show that the resonance frequency is a key parameter for the energy convertor system. Besides harmonic distortion will appear in the induced electromotive force when the end of magnet assembled in the linear generator goes into the space of the outer yoke tooth.