Abstract: Infrastructure-as-a-Service (IaaS) frees users from the trouble of self-management of computer hardware, and provides users with anytime, anywhere on demand computing and storage resources. Eucalyptus is an open source IaaS framework implementation which is used for research. However, there is no paper describes how to use all the modules of Eucalyptus to supply security infrastructure service. In accordance with the security requirements of IaaS, a trusted IaaS framework is provided. The framework provides infrastructure service in five steps, and designs protocols which based on Trusted Platform Module (TPM) to achieve these steps. During the designing process, the use of TPM is strictly standardized and trusted third party is concerned in order to restrict the power of service operator. All the protocols pass the security examination of automatic analysis tool-Scyther, so the conclusion that the framework meets the requirements of IaaS is generalized.