Assessment, as a pillar and one of the most essential components of teaching and learning practice in higher education, has drawn attention from educators, teachers, and pedagogical researchers. Generative Artificial Intelligence (Generative AI), as a fast-evolving technology, would impact planning education and practice, and might change the way how assessment should be designed for planning students. The overall aim of this research is to provide a better understanding of how Generative AI change the way of designing authentic assessments and to provide prompts that enable further in-depth discussion and rethinking of how to adapt and appropriately use Generative AI in the design of authentic assessments in the subject area of Town and Regional Planning. A multi-methods approach combining literature analysis, questionnaire survey, and a focus group was adopted. The literature analysis provided an overall understanding of the research context about how various subject areas treat Generative AI in higher education. A questionnaire survey in a planning society, managed by the Planning discipline at the University of Liverpool, consists of educators, practitioners, and students, and the focus group involving frontline planning educators were conducted. The study collected experience, opinions and thoughts in real-world teaching, learning, and practice, which provided a better understanding of how Generative AI, as a newly emerging, fast-involving, and disruptive technological tool will affect planning education and the requirements of knowledge and skills in the contemporary planning industry, and how the industry should adapt to the transition.