Negotiation is gaining recognition as a vital tool in both public and private urban planning. Planners need special knowledge for the formal roles of negotiator or mediator, and for informal roles as advocate or facilitator, in interactions with government agencies, developers, community organizations, and other special interest groups. A review of the negotiation literature was conducted to formulate a "practical theory" for practicing planners, trainers, and researchers seeking to understand how to negotiate more effectively. The theory statement is presented on two levels. First, two general conceptual frameworks for understanding the process and dynamics of negotiation are formulated. Key and sub-variables identified in the literature are divided into: a) those considered in each of seven developmental stages, and b) those consistently monitored throughout the negotiation. Second, a detailed model of negotiation is developed with tests to measure adequacy of the variables and recommendations for action, if needed. The complete model provides the planner/negotiator with a useful guide for addressing the complex, multi-issue, multi-party conflicts that too often thwart public and private efforts needed for community progress. The model also serves as an elaborate statement of theoretical propositions that can stimulate academic discussion and the formulation of future research designs. / Ph. D.