Permanent magnet synchronous generator (PMSG) are commonly used in direct-drive wind power generation systems, which produce high efficiency, high reliability and low cost in wind power generation. This paper presents a new and simple control scheme using predictive control, which is used in PMSGs and grid-connected inverters. The controller uses the models of PMSGs and grid-connected inverters to predict on each sampling interval. A cost function defines the desired behavior of the system. The switching state that minimizes the cost function is selected and applied during the next sampling interval. At any wind speed within the operating range, the PMSG rotor speed can optimally controlled to extract maximum wind power. The simulated results show that the proposed control scheme can provide the direct-drive wind power generation system with the maximum efficiency and high dynamic performance.