Purpose – The purpose of this paper is to investigate the tribological properties of novel phosphorous-nitrogen (P-N) type additives in water. Design/methodology/approach – The tribological properties of the novel P-N additives in water are compared with a commercial lubricant additive of the P-N type using a four-ball machine. The tribological mechanism was investigated by X-ray absorption near-edge structure (XANES) spectroscopy. Findings – The experimental results indicate that the phosphoramidate derivatives possess good anti-wear and friction-reducing properties. The XANES analysis shows that the prepared compounds can form a protective film containing phosphate and/or polyphosphate that affects the tribological behavior. Originality/value – The purpose of this paper is to investigate the tribological properties of the novel P-N type additives in water.