The present invention provides a prepreg obtained by stretching a material comprising, as a main component, an ultra-high-molecular-weight polyethylene having an intrinsic viscosity of 5-50 dl/g as measured at 135 o C in decalin, to a total draw ratio of at least 20, subjecting the resulting stretched polyethylene material to a splitting treatment, and impregnating the resulting material with a thermosetting resin, and a process for producing said prepreg.
The split stretched polyethylene material has improved adhesion to the impregnant resin and can be used as a good base material for prepreg.