Abstract: The exterior and interior characteristics of welding bead of laser welded 20% SiC/6061 aluminum matrix composites were studied.Laser welded the bead of aluminum matrix composites was nalTow and the ratio of pentration and width was great.The welding bead could be dividedinto three parts:the center melt reaction section and melt unreaction sec-tion and heat affeted section.Many A14C3 platelets were created in the center melt reaction section and made the welding bead brickle and easy to be ruptured.