To estimated the acid phosphatase activity (APA) in soil covered with potato and prairie in Catambuco, place Pasto, Colombia; located to 2820 msnm and with average temperature of 12.4oC. The acid phosphatase activity obtained the biggest values in soil covered with prairie in winter time, in addition to that, there were high correlations between the APA and the organic matter off the soil. In the factors sampling times and use of the soil, there were significance statistical differences, with the most significance in soil covered with prairie and with recent use in potato cultivation. The APA obtained the biggest percentage in soil covered with prairie, in front of the soil cultivated with potato for the two evaluated times. Key words: Acid phosphatase activity, use of land, Solanum tuberosum