The microst ructures at the interfaces of the aluminum matrix composite reinforced by Al
2O
3 particles
were characterized by means of high resolution t ransmission elect ron microscopy (HRTEM). It was revealed that Al(200) and Al (111) planes of the Al matrix should first grow along the surfaces of the Al
2O
3 particles, such orien2tation relationship as Al (200)
∥ Al
2O
3(101 2) and Al [ 011 ]
∥ Al
2O
3 [ 0221 ], and partial-coherent interface exist in one of the interfaces between the Al matrix and the Al
2O
3 particles, a coherent relationship with Al(111)
∥ Al
2O
3 (1120) appears in another interface, but no resultant production is found along those interfaces. Frank partial edge dislocation with 1/ 3 [111 ] Burgers vector, which is responsible for forming of remarkable lat tice deformation field with the scale about 20~30 atomic planes, is observed within the Al mat rix near the interface, however, no dislocations and other defect s are found within the area of the
Al
2O
3 particles near the interfaces. At the same time, the mechanism for forming the interface features is analyzed from the viewpoint of crystallography.