Using polypropylene ( PP) and ramie cloth as raw materials, and maleated polypropylene (MAPP) as the compatibilizer, the composites were compressed at 175℃ under 5, 10, 15 and 20 MPa , respectively. The effects of the mass fractions of both MAPP and ramie cloth and pressures on the mechanical properties of the composites were investigated. The maximum tensile strength of 46. 72 MPa and flexural strength of 68. 43 MPa of the composites are obtained when 3 % and 5 % MAPP are used, which are increased from those of the composites without MAPP by 50.95 % and 61. 81 % , respectively. Both the tensile and flexural moduli increase because of the application of MAPP, while the elongations at break will decrease. When more ramie cloths are used, the modulus always increases; the composites containing 10 % or 20 % ramie cloth have greater strength when formed under lower pressures (5, 10 MPa), but no regulations can be found for the effects of pressures on the strength when the mass fractions of ramie cloth are more than 20 %.