With the accelerated development of urbanization human’s activities are playing an increasing negative impact on ecological security of atmospheric environment especially for urban movement. In order to manage the statement of urban ecological security of air environment as well as its spatial and temporal trends, several measures and methods for resolving the issues are provided in the paper. An assessment system is established with 19 factors and 4 sub-systems based on the atmospheric environment characteristics of Changde through adopting the Pressure-State-Danger-Response (P-S-D-R) model. For guaranteeing the reliability of results two methods are used to determine the weight. The final assessment results indicate that from 2005 to 2009 the composite index for ecological security of atmospheric environment in Changde lies between 0.27-0.87 and the overall trend of quality for ecological security improves gradually which turns to fluctuate between less and more secure and the security threat is not avoided.