To solve the limitation of motion synchronization measurement method applied to medical rehabilitation in most laboratories, a new method to measure the change of metabolic costs with or without a military exoskeleton on an external field environment has been proposed. The relationship between oxygen consumption and heart rate in male subjects aged 20- 30 years is analyzed and an equation that estimates oxygen consumption by heart rate was derived using a multiple regression analysis. An evaluation model which verifies the effectiveness of military exoskeleton was established for specific military scenarios utilizing exoskeleton. As a result, the proposed method is simple and effective for quantitative evaluation of exoskeleton system and can be a substitute of the evaluation methods for the metabolic costs or movement synchronization between human and exoskeleton.