A power transmission mechanism of a model vehicle capable of mechanically performing accurate straight running and turning control without relying upon the output characteristic of each drive system in an RC tank having two drive systems. The power transmission mechanism comprises a motor (10) for traveling providing a drive force for traveling, a motor (30) for turning providing a drive force for turning, a left side differential gear (40) and a right side differential gear (50) to which the rotations of the motor (10) for traveling and the motor (30) for turning are transmitted, and a center differential gear (80) to which the rotation of the motor (30) for turning is transmitted. The turning is performed by using the left side differential gear (40), the right side differential gear (50), and the center differential gear (80).