Cloud computing is expected to provide powerful and easy-to-use model for application design, development, operation and maintenance. There are mainly two models of cloud: IaaS and PaaS model. In IaaS model, application developer and operator have the biggest flexibility for they can control owned virtual machines and most resources totally, but this model needs high technical skills in application development and operation phase. PaaS model claims easy to development, deployment and maintenance, but all these advantage are based on the specific programming model and application architecture. Migration to PaaS cloud for existing applications usually brings big effort and cost increasing. In this paper, we discuss the advantages and disadvantages of the two models from enterprise class application developer angle. Then present an application lifecycle model in which developers could design, develop and deploy their application or legacy systems without programming limitation and migration effort. The application lifecycle model takes application as the centric concept and supported by a set of cloud platform tools. We discuss the application lifecycle framework defined in this model, and then we discussed the possible supporting cloud architecture. © 2011 IEEE.