Abstract: Alumina and carbon short fibers reinforced Al-12Si aluminum alloy hybrid composites were fabricated by squeeze casting.The tensile test and theoretical analysis of high temperature(300℃)tensile strength of the hybrid composites were carried out.The rule-of-mixture(ROM)of tensile strength of the composites was developed and modified based on the foundation of comprehensive factors,including the change regularities of fiber-length,dislocation-strengthening resulting from residual stress and dispersion-strengthening of fibers.A new model was established for prediction of high temperature tensile strength of alumina and carbon short fibers random-orientation reinforced Al-12Si metal matrix hybrid composites.The theoretical results based on the new modified model agree well with the experimental results.The model established in this paper was proved to possess validity and practicality to a certain degree.