Abstract: Based on the ‘three critical points’ theory of eco-fitness, and by using dynamic weighting and fitting methods, an assessment system for the eco-fitness of county-level agricultural leading industry structure was constructed, and, taking Zhangqiu of Shandong Province, East China as a case, the eco-fitness of county-level agricultural leading industry structure was assessed and predicted. Due to the limited agro-ecological resources, the comprehensive eco-fitness index of four kinds of agricultural leading industry in Zhangqiu presented an upward trend from 2005 to 2010, but a downward trend from 2011 to 2015. The eco-fitness indices of oil crops and fruits would be negative in 2015. The applied research in Zhangqiu confirmed the validity of the assessment system constructed for the ecofitness of county-level agriculture leading industry structure and the rationality of the prediction model.