Based on ecological footprint(EF) model,EF distributions over time and space were determined in Huaihai Economic Zone from 1986 to 2008,and the eco-system sustainability was assessed on the twenty city members of the Zone.The study shows that regional EF per capital had increased rapidly by 5.74% per year.In 2008,the four highest EFs was observed respectively on cities of Laiwu(9.143 6 hm²),Zaozhuang(6.340 4 hm²),Huaibei(6.185 2 hm²),and Jining(5.004 9 hm²),and the four lowest EFs respectively on Fuyang(1.038 5 hm²),Zhoukou(1.122 1 hm²),Suqian(1.209 7 hm²),and Kaifeng(1.319 5 hm²).For all cities,the largest EF was as approximately nine times as that of the smallest.Among the six types of land,energy land was the most important factor that contributed to EF differences.Total ecological capacity(EC) per capital decreased slightly,and ECs of all cities ranged between 0.4~0.7 hm².Ecological surplus was found in 1986,1987 and 1988.After 1989,ecological deficits(EDs) become increasingly larger as 1.692 1 hm² in 2008,with an annual increasing rate of 29.08%.Therefore,the EFs had been over demanded substantially by the ECs,which were continuously consuming the natural capital stocks to compensate EDs,threatening ecological security of the economic system.According to ecological sustainability index(I^ES),more than half of the cities had I^ES lower than the critical value for the state of "moderately non-sustainable",within which cities of Laiwu,Zaozhuang,Huaibei,Jining,Taian,Xuzhou and Rizhao were classified as "strongly non-sustainable cities".Finally,at a perspective of regional scientific development,countermeasures and suggestions have been addressed to promote sustainable development in all cities of Huaihai Economic zone.