SiCw/Al composite was fabricated through a squeeze cast route and cold rolled to about 30%, 50% and 70% reduction in thickness, respectively. The length of whiskers in the composite before and after rolling was examined using SEM. Some of the rolled composites were recrystallization annealed to remove the work hardening of matrix alloy. The tensile strength of the rolled and annealed SiCw/Al composites was examined and then associated with the change of the whisker length and the work hardening of matrix alloy. It was found that the tensile strength is a function of the degree of cold rolling. For the cold rolled composites, with the increase in the degree of cold rolling, the tensile strength increases at first, and decreases when the degree of cold rolling exceeds 50%. For the annealed ones, however, the tensile strength decreases monotonously with the increase in rolling degree. The different changes in tensile strength between the rolled and annealed composites could be attributed to the result of the competition between the work hardening of matrix resulting from the cold rolling and the work softening arising from the change of whisker length.