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Knowledge of the mechanisms of water infiltration in sand dunes and wadis is a key to understanding the hydrological conditions in and and semiarid regions. To trace infiltration processes in sand dunes, an artificial rainfall infiltration experiment was conducted in a typical sand dune in Al Ain, United Arab Emirates. Thermal: sensors and tensiometers were set at two sites, a rainfall test site and a natural site, at depths of 10, 30, 60, 120 and 200 cm, respectively. For a start, the, variations in temperature between the sites Were compared with tension as well as soil water at the same depths. Field observations showed that-the temperature of the sand dunes at the rain experimental site was affected more strongly by air temperature than that at the natural site, which means that-temperature distribution in the sand dune has a very close relation: with the water content. Then, the scheme combined with temperature difference and moving average was tested in tracing the temperature-variation with movement of the infiltration front. It was found that the vertical temperature correlated well with the water movement in the sand dune, from which the average velocity of infiltration was estimated at 3 cm/h.