Abstract:Salt accumulation and nutrient unbalance exist in soils under protected cultivation in Yuxi City, Yunnan Province. Chemical properties were compared between the soils of protected and open fields by testing samples collected from paired soil profiles in the protected and open fields. Results showed that the pH value in the protected field was lower than in the open field, but and the salt concentration, organic matter, available N, P, K, S, Cu, Zn and Fe, and exchangeable Mg were higher, and exchangeable Ca and available Mn did not differ much between the pairs. Enriched nutrients were distributed mainly in the 0~10 cm layer and concentrated in 0~2 cm top surface, especially for EC value, available S, K and Mn.