Abstract: Besides grain, cotton is the most important agricultural products and strategic supplies,with the longest industrial chain and the highest industrial relevancy in China.The cultivated land,as the most valuable farming resources,plays a crucial part in cotton production.Xinjiang is the largest cotton-producing area in China,which owns a particular climate condition and geographical advantages,such as temperature and light.However,with the unordered expansion of cotton acreage,the problems of scarcity of cultivated land and deterioration of ecological environment have become more and more prominent in recent years.This paper analyzed the spatial-temporal pattern,contribution factors,evaluation of cultivated land ecological security about the cotton production in Xinjiang Province,by using agricultural production statistic data from 2000 to 2015.The methods of the spatial auto-correlation,production contribution and PSR model were implemented in this study and finally the theoretically reducing cotton sown area at county level was generated.The results indicated that the spatial pattern of cotton production has been significantly changed since 2000,the main cotton-production areas had been formed in northern and southern slopes of Tianshan,the trend of "increase in south and decrease in north" was significant,the high value zone of per unit yield was expanded to both sides of Tianshan,which formed the concentrated high-value center; the cotton production displayed certain spatial clustering effect; the high value clusters with continuous stability were mainly distributed in south Xinjiang; the factor of total sown areas,rather than the per unit yield and structural adjustment,had significant impact on cotton production contribution rate from 2000 to 2015.The evaluation result of cultivated land ecological security was less than 0.6,which meant a critical safety or less safety state.The proportion of type IV (the less safety type) and type V (unsafety type) was 84.21%,and the regions of these two types were concentrated distribution.The total theoretic reducing cotton sown area in Xinjiang was 101.176×10⁴ hm²,and the regions of reducing sown area were mainly distributed in south Xinjiang,which accounted for more than 60% of the total area.Based on the analysis,the institutional restraint of water resources and land management,the efficiency of agricultural irrigation water and alternative crops plantation should be taken fully into account in order to improve cultivated land ecological security.

Key words: cotton production, cultivated land ecological security, spatial auto-correlation, production contribution rate, PSR model, Xinjiang