Abstract: The quantity of moisture transmitted through leather under different environment conditions was measured with self-made instrument,and the effect of ambient temperature,relative humidity and so on of the leather garment during wearing on its moisture permeability was evaluated using grey system theory.Quantitative analysis of each factor on the moisture permeability was conducted,and it revealed that they were in such an order: ambient temperature>pressure>relative humidity >time of moisture transmittance.Since the environment factors are influencing on each other and rather complicated,the results evaluated by means of grey system theory have certain degree of confidence,thus providing a scientific basis for researchers to design comfortable leather clothing for adapting the change of environment.