In this research, Ag/CuO were synthesized from silver nitrate, copper nitrate and sodium carbonate by copper precipitate method and soak method. Proportions of silver/copper mono-oxide by quantity are (0:100), (2:100), (6:100) and (10:100). The authors appraised product crystal structure by XRD and SEM methods, at the same time the authors also surveyed material antibiotic activity with Escherichia coli strain by agar streak method. The result showed that, materials are seed, ball shape. Copper precipitate method is better than soak method. Copper precipitate method have good crystal structure, best at proportion of 6: 100. All product had antibiotic activity, but material was created with 6: 100 proportion showed best antibiotic activity against Escherichia coli.