Abstract: Modification is made of the traditional model of ecological carrying capacity of cropland through introducing the factor of cropland heavy metal pollution into the study of the ecological footprint theory,with Jiangsu Province set as an example in case study.Results show that by using the modified model the ecological carrying capacity of cropland in Jiangsu in 2005 was calculated to be 0.127 hm² per capita,5.2% lower than 0.134 hm² per capita calculated by using the traditional model;the cropland ecological deficit 0.067 hm² per capita,11.7% higher than 0.060 hm² per capita calculated by using traditional model;and the cropland ecological sustainability index 0.39,lower than 0.41 calculated by using traditional model.Although the results of the calculation using both models put the cropland of Jiangsu under the category of "weak unsustainability",the modified model more truly reflected the practical situation of the land use,and the negative impact of heavy metal pollution on ecological carrying capacity of the cropland in Jiangsu Province as well.

Key words: ecological carrying capacity of cropland, cropland use, ecological sustainability index, heavy metal pollution