Two new 14-membered cyclopeptide alkaloids, Oxyphylline B (4) and Oxyphylline C (5), along with three known 13-membered cyclopeptide alkaloids, were isolated from stem and roots of Zizyphus oxyphylla Edgew. The compounds were tested for antibacterial activity. Oxyphylline B (4) showed comparatively better antibacterial activities against Escherichia coli (MIC, 5 mu g/mL) than other compounds. This compound also exhibited weak antimicrobial activities against Staphylococcus aureus (MIC, 25 mu g/mL), Pseudomonas aeruginosa (MIC, 50 mu g/mL) and Salmonella typhi (MIC, 50 mu g/mL).