A rotary device was built in a home microwave oven, where wet soybean was dried in a dynamic moving state to improve the microwave drying uniformity. Experiments were conducted to investigate the relative water removal ratio which was defined to characterize the electromagnetic field distribution in microwave oven, and to compare the drying characteristics between static and rotary microwave drying. It is concluded that the kernel cracking ratio is lower when microwave drying of soybean was carried out in rotary state. Higher unit microwave power input results in rapid removal of water from soybean but an increase of kernel cracking ratio.