The Saker Falcon（ Falco cherrug
） is listed as a second class state protected wild animal, mainly distributed in the western provinces of China. From March to July in 2005, the breeding ecology of the Saker Falcon was investigated at the eastern fringe of Junggar Basin, Xinjiang. The results showed that the breeding season of the Saker Falcon was from April to July. The clutch size varied from three to five and the average size was 4.0±0.63. The average length of the eggs were 55.40±3.06 mm and the breadth, 41.11±1.70 mm. The hatchability, survival rate and fecundity of the Saker Falcon were 70.8%, 64.7% and 1.8 respectively. The nest success rate was 83.3%. Their growth changes in body weight and tarsus length, followed a logistic growth curve. In Xinjiang, food is the key factor on clutch size and fecundity for the Saker Falcon. To better protect this Falcon, their habitat should be further protected to maintain a higher prey diversity and abundance, which is essential for the Saker's conservation.