The macrofauna is an important component of ecosystems because its participation in the biodegradation of soil nutrients has beneficial effects on the food chain. During six months, from February through July, a number of worms and their biomass (g m-2) were assessed in the soil of the Estación Experimental of Kallutaca, located on the plateau of La Paz. A study area of one hectare of fallow land was delimited. The study area had been without tillage activity for approximately ten years. This area was divided into five rings. Each ring had eight sampling points. Each sampling point included a square meter of soil and had a depth of 30-35 cm. The density and biomass of earthworms recorded in this study were 13.6 ± 29.74 m-2 and 4.7315 ± 2.3544 g m-2, respectively. The average length of the earthworms was 4.7960 ± 0.6219 cm. The environmental characteristics of the study area may influence the development of these earthworms