Air and ground freezing-thawing index for stations in the Heihe River Basin were calculated based on daily mean temperature,and its variation characteristics and time series were analyzed. The results showed that, the freeing index over the Heihe River Basin were influenced by elevation and latitude while the thawing index mainly influenced by elevation; air freezing-thawing index and surface freezing-thawing index ranges were 673 ~ 2 135 ℃·d,1 028 ~ 4 177 ℃·d,682 ~ 1 702 ℃·d,1 956 ~ 5 278 ℃·d,respectively; freezing index exhibited decreasing trend and the slopes of air freezing index (1951-2007) and surface freezing index (1954-2005) were - 56. 0 ℃·d /10a and - 35. 4 ℃·d /10a; thawing index increased and the liner tendency of air thawing index was 47. 8 ℃·d /10a during 1951-2008; surface thawing index decreased during 1954-1975 with a rate of- 135. 9 ℃·d /10a and increased during 1976-2006 with a rate of 185. 3 ℃·d /10a. Freezing index was influenced by both elevation and latitude while thawing index was mainly controlled by elevation in the Heihe River Basin. We also found that there was a strong liner relationship between mean annual air temperature and freezing-thawing index.