Abstract: Security warning of the cultivated land resources is an effective means to protect arable land and realize the sustainable utilization of cultivated land resources. Taken Heilongjiang province as the research area in this paper, the safety warning index system of cultivated land resources was established from the perspective of cultivated land protection and by combining with the three aspects including the quantity, quality and ecological environment of cultivated land. Security quantitative evaluation value of cultivated land resources in 1996-2008 was taken as basic data in study area and the longitudinal judgment method was used to determine threshold value of safety degree for cultivated land resource in research area. And GM (1.1) and the BP neural network technology were used to forecast and analyze the change trend and safety degree of cultivated land resources from 2012 to 2015 in Heilongjiang province, and then security warning system of cultivated land resources was constructed. The results indicated that safety values of cultivated land resources appeared to irregularly decline from 1996 to 2008 in Heilongjiang province. Warning degree of cultivated land resources in 2012 were slight, and that from 2013－2015 was middle and its situation was became worse. The quality of cultivated land descended while quantity of cultivated land increased in 2012, and the quantity of cultivated land increased slightly from 2013－2015, but the quality of cultivated land continuously decreased. The ecological environment gently rose from 2012－2015. So during warning period, incoordinative development between quantity and quality of cultivated land resources quantity caused to warn in Heilongjiang province, and the urbanization level, water and soil loss ratio and resilience index and so on were the sensitive factors to affect of security conditions of cultivated land resources in Heilongjiang province. This paper provides a reference for a relevant pre-warning research.