The contactless power transformer systems (CPTs) have recently attracted much attention as it is possible to supply electrical energy to mobile vehicles without cables. 300kW class CPT systems are required for railway vehicles power feeding applications. In this power range, there are some technical problems such as higher reactive power due to longer gap and power control at the misalignment of ground coils and on-board coils. To cope with these problems, authors have been working to establish a reactive power conscious coil designing method and less loss type power conversion system with controlling active power in the secondary side. In this paper, some of these results are presented