By the use of annual mean temperature data of 24 meteorological stations in Ning xia, the homogeneity test was studied for annual mean temperature time series with the Po tter method. The results showed that among the 24 series, the 9 series were inhomoge neous, and the other 15 series were homogeneous. The discontinuous points were mainly found in the years 2001-2 006 an d altogether had 7 discontinuous points (77.8%), in which 6 inhomogeneous series were caused by r elocated stations. Stations were relocated frequently in the 1950s, but the ti m es of relocated station were not the main causation of inhomogeneous series, a nd the environment changes of relocated station were the main factors. Moreover, the environment townish change of a station was also one of the factors, even though the station does not move.