Networked manufacturing technology has provided an effective approach to integrating manufacturing resources over Internet. However, a vast number of resources involving networks, computing, and storage resulted in ever increasing energy consumption. This paper proposed an IT energy-saving approach based on Cloud Computing for networked green manufacturing. The paper first presented the architecture of networked green manufacturing on Cloud Computing to support service-oriented IT resources outsourcing. Then the paper discussed the dynamically-scalable resource utilization mechanism for networked manufacturing. The approach can provide effective support for manufacturing resource virtualization and deliver a variety of services to distributed manufacturing enterprises. Moreover, IT resources of network, computing, and storage can be shared concurrently and scheduled dynamically that are adaptive to practical resource demand of collaborative manufacturing tasks. Thus, a great amount of IT resources can achieve high efficient utilization in networked manufacturing and result in reduced energy consumption to benefit green manufacturing.