[Objective] An comprehensive evaluation index system of urban land ecological security was established and the dynamic change of land ecological security and the main obstacle indicators were analyzed in 2004, 2009 and 2014. These were expected to provide bases for regional land use decision-making and ecological maintenance.[Methods] Dynamic evaluation and land ecological security were analyzed using grey relation projection model, dynamic degree and standard deviation. The obstacle indicators and its degree of land ecological security were measured by obstacle degree model.[Results] (1) The total degree of land ecological security during 2004-2014 increased slowly, but generally it was still in a lower level. The environmental subsystem had experienced two stages from slow promotion to gradual degradation; simultaneously, the economic one also had experienced two stages from rapid promotion to slow promotion; meanwhile, the social one always had been in a slow promotion stage. The internal coordination degree of land ecological security was improved gradually. (2) The categories, the obstacle degree, and the order of obstacle factors of land ecological security were all in dynamic change, the obstacle factors had evolved from economic factors to resources and environmental types. (3) In order to treat these problems exposed in land ecosystem security, it should be proceed with sustainable land use and healthy urbanization, hereby to achieve the coordinative development among economy, environment and the society of Nanchang City.[Conclusion] The evaluation results of land ecological security research were thought accordant with the objective reality. In view of the main problems exposed to the land ecosystem, relevant countermeasures are put forward wherein.