Abstract: The fiber compaction curves of unidirectional fiber cloth were measured by the equipment designed by theauthors , and fitted curves were obtained using Gutowskips compaction equation. A parameter describing the compressibility was proposed. By using this parameter , several factors which affect the compressibility were studied ,including the initial fiber volume f raction , number of layers , variety of lubricated medium , way of layup and the variety of fiber. The result s show that the initial fiber volume f raction , number of layers and variety of lubricatedmedium have no remarkable effect s on the compressibility of the unidirectional fiber cloth. The state of whetherfibers are lubricated , the way of layup and the variety of fiber influence the compressibility significantly.