The evolution of the dislocation boundary structure during the cold rolling of the AA3104 aluminium alloy was investigated using electron channelling contrast imaging and electron backscattered diffraction techniques. The results showed that there was a strong correlation between the dislocation boundary structure and the grain orientation. No strong effect of strain level or second-phase particles on the structure-orientation correlation was found. Based upon these observations, the microstructures could be classified into one of three types: type-A grains, containing two sets of geometrically necessary boundaries, type-B grains, containing one set of geometrically necessary boundaries, and type-C grains, consisting of a structure of large dislocation cells. Grains with a type-A microstructure had orientations near the copper, brass, and Goss orientations; grains with a type-B microstructure were primarily near the S orientation; and grains with a type-C microstructure had orientations near the cube orientation. The alignment of the extended dislocation boundaries depended strongly upon the grain orientation. In most grains, the boundaries were parallel to the traces of the most active {111} slip planes, as identified by a Schmid factor analysis Dislocation Boundary Structure from Low to Medium Strain of Cold Rolling AA3104 Aluminum Alloy. Z.Yao, G.Huang, A.Godfrey, W.Liu, Q.Liu: Metallurgical and Materials Transactions A, 2009, 40[6], 1487-97