Prof Ling was the Director of Planning of the HKSAR Government (2012-16) and the President of Hong Kong Institute of Planners (2007-09). He is currently serving HKSARG as the Strategic Planning Advisor for Hong Kong/Shenzhen Cooperation.
He has been appointed by The Hong Kong Polytechnic University as Professor of Practice (Planning) and the Director of Jockey Club Design Institute for Social Innovation. He is also the Adjunct Professor of the University of Hong Kong and the Chinese University of Hong Kong, and the Associate Fellow of the University College of Estate Management, UK.
He also serves the community as the Vice Chairman of the Hong Kong Housing Society, Director of the Cyberport Management Ltd. and Chairman of its Entrepreneurship Committee, and the Chairman of the Country and Marine Parks Board.