The length changes of different preheated SiCp/Al composites with varied compositions prepared by pressure free infiltration method were measured by TMA （thermal mechanical analysis） after heat recycled at 20～180 ℃

in which the unite length changes

mamely residual strain

was used to analyze the dimensional stability.The results show that residual strain occuring in heat recycled SiCp/Al composites is reduced to be a constant value with the increase of heat recycling times.There exists different residual strain at different pretreatment

in which the minimum residual strain can be obtained by cooling-heating recycled pretreatment.SiCp/Al composites with a big particle size and hard matrix possesses a higher dimensional stability after heat recycle.