The knowledge of soil moisture spatial patterns provides basic but important information in the studies of hydrological processes. This research aims to describe soil moisture spatial distributions using two complementary approaches: geostatistics and maximum entropy theory. Surface soil moisture surveys are being conducted in a 5-ha grassland at the OSU Range Research Station near Marena, OK. Semivariograms and the maximum-entropy probability distributions of soil moisture from this experiment will be presented and compared.  The scale-invariant properties of soil moisture spatial-distributions at the field-scale will be described.