The biggest problem in use of the planetary gears is uneven load sharing of every planet gear. For solving the problem, many new designs have been offered, but there is not an exact method to confirm their results. Applying the principle that the shearing strain on the beam is constant in one side of the loaded point, a new measurement method of detecting the shearing strains on the planet gear exes is offered. The measurement by the method is done on actual planetary gears using the power circulation type test rig. As a result it is made clear that the offered measuring method of the load sharing in the planetary gears is practically useful and that the dynamic load sharing condition in actual planetary gears is considerably different from the estimated one from the static condition.