Based on distribution of greenhouses in Ningxia, soil samples were collected randomly from 0~30 cm topsoil layers of croplands and greenhouses located in different regions. Variability of the contents of N,P and K in the tested soils was analyzed.The results showed that the contents of N,P and K in the greenhouse soils were generally higher than that in the soils of open field.In terms of relative accumulation, the nutrients in greenhouse soils were in the order of nitrate N > available P > readily available K > alkali-hydrolyzable N > total P > total N. The contents of these nutrients in the greenhouse soils showed a certain feature of geographic distribution. The contents of N and K (except for P) of the soils were generally higher in the irrigation region than in the mountain region, but the variation coefficients of all the nutrients were obviously the other way round. The differences in average contents of soil N, P and K between the six counties, Pingluo, Xixia, Xingqing, Qingtongxia, Zhongwei and Yuanzhou, were insignificant, but significant between the six and Yanchi County, which was the lowest in these soil nutrient contents.