Rapidly solidifed Al-Cr-Zr alloy specimen was made by atomization and splats quenching method. The calculated cooling rate ranges from 10^6 K/s to 10^7 K/s, and as-quenched microstructure consisted of a very fine dendritic or cellular zone, and interdendritic segregation was not suppressed for Al-Cr alloys. We obtained a grain size of 1-5㎛. The Al-Cr-Zr alloy evidently shows an age hardening response and peak hardness was observed at the specimen which held at 450℃ for 1 hr. Agglomeration of precipitates having a agglomeration size of 0.5-2㎛ and a precipitate size of 300-800Å was observed for the first time. In this study we also studied the precipitation behavior during isochronal aging by TEM and X-ray diffractometer.