La-doped Mg/Al layered double hydroxide (LDH) was synthesized and intercalated by sodium dodecyl sulfate. Friction properties of LDHs as lubricant additives were evaluated in four-ball friction and air compressor test. The results showed that Mg/Al/La-LDH was prepared with La/Al molar ratio of 0.1. The interlayer spacing was expanded from 7.662 to 25.663 angstrom after intercalation. The intercalated product exhibited better tribological property than its precursor in the friction tests. The improved performance was attributed to a reduction in friction between the expanded laminates, good dispersion of the nanoparticles in the medium and an effective tribofilm formed on the contact surfaces. (C) 2015 Elsevier Ltd. All rights reserved.