In the ICT area, we are facing with emerging domains of standardization such as Smart Cities, Big data, Internet of Things, Cloud computing, Smart Machines, 3D Scanning & Printing, and many other forthcoming emerging domains. Key commonality of these emerging domains involves the characteristics of complex systems. The emerging areas are influenced by multi-facets of complex sphere. To deal with emerging domains in standardization, Korea Agency for Technology and Standards (KATS) has lead standardization framework activities in Korea. From the above activities, we have learned that following issues should be carefully considered to deal with the complex characteristics of the emerging domains: Treatment on Horizontal vs. Vertical Domains, Value proposition, Unambiguous and Useful Guide, Participants (stakeholders and experts), Verification and Validation.