Today, we have various production in plays and operas, in which settings tend to be larger and heavier. But these settings are restricted in size and weight by insufficient flying loads and they can't produce enough. So we have to reconsider about the stage machinery, especially, the flying load. It is important process in the planning of theatres to plan the stage machinery. This study compares the data of 20 years ago with today state and aims to make data for the planning of theatres and the flying system in them.