In this study, impacts of four types of monoglycerides and four types of triglycerides, which serve as additives, on properties of water-based drilling mud were explored using a ball-on-disk tribometer. It was found that the addition of glycerides increased the viscosity of drilling mud slightly. The results of tribological experiments indicate that carbon chain length, level of unsaturation, and polar groups of additives are three key factors which determine friction reduction and anti-wear behaviors of the drilling mud. The formation of a denser and thicker protective film on steel surface due to presence of glycerides additives is attributed to observed better friction reduction behaviors.