Abstract: Cultivated land，the basic material and groundwork of human survival and development，is a kind of non-renewable and scarce resources. The intensity，deepness and type of using land that is threatening the safety of cultivated land directly changes enormously with growing people and rapid urbanization from reform and open to the outside world. Altay City，Xinjiang，China is one of the National Basic Farmland Protection Demonstration Areas in China. Therefore，it is of great importance to protect the high-quality cultivated land and improve the comprehensive production capacity of cultivated land of Altay City for the food safety，social stability and ecological security of Xinjiang. As such，this paper selected the cultivated land resources of Altay City as the study object.  Based on the theory and means of warning-signal of cultivated land，this paper constructed the warning-signal target system of cultivated land resources from the aspects of its quantity，quality and ecological economic environment，and filtered the most powerful factors，such as the per capita cultivated land area，total cultivated land area，per acre grain yield，PFER by the method of AHP. According to the analysis of existed warning signal of cultivated land in Altay City from 1995 to 2010，this paper figured out why its warning signal is aggravating. The reasons are as follows: on one hand，the adjustment of agricultural structure，cropland conversion and increasing population have lead to the decreasing of total cultivated land area and per capita cultivated land area; on the other hand，the soil condition and secondary salinization are so serious that the quality of cultivated land is falling，its ecological economic environment is deteriorating and warning signal is aggravating. Besides，this paper also forcasted the cultivated-land warning signal of Altay City in 2012- 2020 by Forecasting Model.  The results show that: the warning signal of per capita cultivated land area will be low in the long run; there will be no warning signal of total cultivated land area within 10 years; the warning signal of per acre grain yield will increase step by step，and reach the highest point in 2020；the warning signal of PFER is relatively serious; the comprehensive warning signal of cultivated land resources in Altay city will increase year by year.  Facing the increasingly serious alert of Altay City cultivated land resources，we have to combine with the present using situation of cultivated land resources，strictly control the scale of non-agriculturalization of cultivated land，increase the agricultural investment in science and technology，speed up to decrease the soil salinization，fully exploit the potential yield of cultivated land，enhance the fertility and economic benefit of the cultivated land，strengthen the comprehensive improvement of the cultivated land，effectively improve the quality of cultivated land，protect its ecological and economical environment，and really realize the dynamic equilibrium of the total amount of cultivated land resources.

Key words: cultivated land, early-warning, cultivated land use, Xinjiang, Altay City