Evaluation on cultivated land ecological security is of greatly importance in improving cultivated land ecosystem and sustainable cultivated land use.On the basis of defining the meaning for cultivated land ecological security,the evaluation index system was established based on the pressure-state-response (PSR)model.And then an empirical analysis was conducted in Sichuan Province by entropy-weighted extension matter-element model.The results showed that:(1)The level of cultivated land ecological security had been gradually improved in Sichuan Province during the period from 2000to 2008,but the coefficient of the correlation for the assessed rank of safer class was very weak in 2008;(2)The factors such as,the pesticide load per unit of cultivated land,fertilizer load per unit of cultivated land,per capita cultivated land,land reclamation rate and extent of soil erosion were indentified as the key constraints for further improvement. Therefore,to improve the ecological security in cultivated land,economic development mode needs to be further transformed,excessive consumption of land resources need to be reduced,green agriculture need to be developed,pesticides and fertilizers need to be applied in a rational way,and environment and soil erosion need to be conserved effectively.