Bauxite and ore-bearing rocks are different obviously from underlying limestone in electrical properties, and this constitutes the basis of applying the transient electromagnetic method to the exploration of bauxite deposits. The little-loop transient electromagnetic equipment was used in the Hucun bauxite deposit and some other deposits. Characteristics of the inversion anomalies were studied. It is shown that the high resistivity is caused by the basement limestone in the bauxite-bearing strata. The predicted interface of high resistivity is identical with the basement limestone interface controlled by drill holes.