A number of authors have reported the influence of abiotic parameters on the spatial and temporal distribution of soil microarthropods (REDDY, 1984; MALLOW et al., 1984; STREIT, 1982; ANDERSON & HALL, 1977; USHER, 1976). It is clear from these studies that microarthropods respond differentially to the environmental factors. USHER (1976) and USHER et al.(1982) stressed the importance of the distributuion of food resources and soul moisture. SCHENKER (1984), working in a mixed deciduous forest soil, found few statisically significant correlations; although the relations between microarthropods and soil features seemed apparent. In deserts, the abiotic effects of climatic extremes of soil moisture and temperature are believed to drive many biotical processes taking place in the soil system (WALLWORK, 1982). The effect of these variables and organic matter on desert soil microfauna has been studied in different ways. SANTOS et al. (1987) reported highly significant correlations between mass of surface litter and density of microarthropods. STEINBERGER & WHITFORD (1985) found correlations between total microarthropods and soil moisture but the the significance of these correlations depended upon site and season. Surveying a desert swale, STEINBERGER & WHITFORD (1985) observed that, whereas overall microarthropod abundance was correlated with soil moisture, some species-populations were not. WALLWORK et al.(1984), working with simulated rainfall, showed that a continuous irrigation regime caused changes in the reproductive patterns of some species of oribatids, but not in others. WHITFORD et al. (1981) observed an increase in numbers and diversity of microarthropods in surface litter within one hour after artificial wetting; nevertheless, a subsequent decrease followed in the still moist litter. STEINBEGER et al. (1984) concluded that water, in the absence of an adequate supply of organic matter, does not stimulate population increase of the soil fauna. MCKAY et al. (1986) showed that soil temperature (or insolation) has a greater effect on overall microarthropod population densities than soil moisture. Thus most studies in deserts have focused on climatic variables and only marginally on soil properties. This study was designed to examine the relationships between abundance patterns of soil microarthropods and soil properties and climate in a northerm Chihuahuan Desert ecosystem.