Repeated maximum stress of 1kgf/$ extrm{cm}^2$ was applied to the 3kinds of cut pile carpet(made from Acryl, Nylon and Wool) to test the behaviour of carpet at the compression process and the following results were derived from it. 1. The relationships between the percentage of compressive distance to the number of repeat, between the percentage of compressive energy to the number of repeat, and between the recovered carpet height to the number of repeat are all well coincide with the linear regression on the fugure of semi-log scale on which the number of repeat is taken by log scale. 2. Wool carpet shows less number of repeat to achieve the state of mechanical conditioning than the number of it from Acryl or Nylon carpet. Wool carpet also shows smaller deformation than that of Acryl and Nylon when they achieved at the state of mechanical conditioning.