Copper and aluminium laminates are alternately stacked and sintered by PAS at T=743K under different pressures. Microstructure of the cross section of the samples are characterized and analyzed by means of Optical Microscope (OM), Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscope (EDS). The results show that the initial Al layers melted and produced Al-rich liquid phase during sintering at T=743K, and the Al-rich liquid phase ultimately formed complicated L layer consisting of the saturated solid solution phase Al(Cu) and the two-phase Al2Cu-Al(Cu) eutectic when the laminates was cooled to room-temperature. The interface between the Cu layer the L layer consists of solid solution(α), Al2Cu3(δ)and Al2Cu(θ) layer. Voids and cracks are not found at or near the interfaces of the polished samples. The most important effect of the pressure is to change the shapes of interfaces, which almost smooth at 10MPa but flexual at 50MPa.