The magnitude of giant magnetoresistance (GMR) of the (Co1O a/Cu1O a) 1 5 superlattice has beenmeasured up to 20 kbar. It is found that the electrical resistivity ρ decreases with increasing pressure at room temperature, having the rateρ - 1 P = -22x10 - 3 kbar - 1 . The magnetoresistance (MR) ratio Δρ/ρ s at 4.2 K slightly decreases with increasing pressure. The saturation field H s also decreases with increasing pressure.