Because the current wind load standard is not suitable for agricultural facilities, it is necessary to establish a more adequate load standard for agricultural facilities. Thus, this study built models for venlo type and wide type glass greenhouses, and conducted wind pressure experiment according to the slope and shape of roof surface. Because there is no accurate standard for agricultural facilities, we compared the external pressure coefficients for gable roofed structures and multiple gable roofed ones suggested in the Korea load standard (KBC-2009) with values obtained from the experiment. For wide type glass greenhouses, the load standard was similar to the experimental value. For venlo type glass greenhouses, however, while the load standard specified that a milder roof slope is more advantageous, the external pressure coefficient obtained from the experiment showed a more advantageous result when the slope was steeper.