The excavators work in harsh environmental conditions.The cabin of the excavator is supported by the rubber mount and dynamic behavior occurs due to large impact during operation. This can cause damage to the cabin.In this paper, the actual PSD of the harsh working conditions is measured and PSD profile for design evaluation is made. The dynamic impact behavior of cabin is predicted by in-house mounting optimization program. By determining the mesured PSD in the actual operation conditions , dynamic impact behavior of a cabin can be more accurately predicted. Therefore, it has increased the possibility of preventing the impact damage of the cabin.