The book deals with complexity, imprecision, human valuation, and uncertainty in spatial analysis and planning, providing a systematic exposure of a new philosophical and theoretical foundation for spatial analysis and planning under imprecision. Regional concepts and regionalization, spatial preference-utility-choice structures, spatial optimization with single and multiple objectives, dynamic spatial systems and their controls are analyzed in sequence. The analytical framework is based on fuzzy set theory. Basic concepts of fuzzy set theory are first discussed. Many numerical examples and empirical studies are provided to substantiate the theoretical arguments and empirical relevance of this approach. The book provides a more comprehensive perspective on uncertainty and a flexible framework for analysis in the real world, for problems such as commonly encountered spatial problems, urban and regional economic problems, and planning problems. Though the treatment is unconventional, it generally includes conventional analyses as special cases.