Current advances in upper air temperature change and its uncertainties were summarized briefly. IPCC-AR4 have been approved warming in the troposphere and cooling in stratosphere since 1958, but emphasized that the uncertainties about trend of long-term change are still substantial. In this paper we reviewed causes of the uncertainties in radiosonde temperature series. The approaches for homogenization were summarized and evaluated. Practices to homogenize temperatures series from 116 radiosonde stations revealed two-phase-regression and hydrostatic methods were suitable in China, and deduced critical maximum missing rate of 30% for examine reliability of the time series. Homogenized temperature series verified long-term change of upper air temperatures in China, with the mid-lower troposphere tending to warm especially after the 1980s and the stratosphere tendeding to cool after 1958.