Abstract: Characteristics of Cu-Al powder alloys of reaction laser sintering are investigated by study on variation process of sintering temperature,transformation of product phase,densification behavior and hardness of samples.It is showed that under laser power 800W and irradiation time 16s,reaction of sample penetrates deeply,characterization of serious and rapid propagating sintering appers,and phases were formed within short time of reaction stage during laser heating.All of the samples shrinks,and metastable martensite(M) Cu3Al is formed in Cu75Al25 alloy.