Abstract: Present paper discusses the influence of irreversibility of desiccation of lateritic soils on their physico-mechanical properties based on the experimental results of two typical laterite. The experimental results show that many property indexes of these soil samples vary obviously after desiccation in comparison with those at natural state, and these variations are irreversible. The mechanisms of these phenomena have been analyzed. It has been noticed that some erroneous decision and judgement should be arisen in solving practical lateritic soils problems if we neglect this important character.