In networked computing environments, it becomes increasingly difficult for normal people to manage privacy, i.e., “to determine for themselves when, how, and to what extent information about them is communicated with others”. The thesis argues that achieving better privacy is not about hiding as much personal information as possible but enabling personal information disclosure at a level of openness that is as close as to a user’s desired level to assist him/her in accomplishing useful tasks. Following Palen and Dourish’s observation that privacy management is a dialectic and dynamic boundary regulation process [Palen03], the thesis argues that no set of pre-specified static privacy policies can meet users' changing requirements for privacy in networked computing environments, and therefore a new approach (i.e., adaptive privacy management) is proposed as the process that a user and/or a system to continuously adjust the system behaviour of disclosing personal information according to the user's changing desire for openness. In this thesis, we propose a set of requirements for adaptive privacy management and i the design and implementation of a middleware that meets these requirements for the target domain of applications that enable intentional sharing of personal information in networked computing environments. The middleware facilitates the creation of adaptive privacy aware applications that allows users or the system on behalf of the user to adjust the balance between openness and closedness; leading to an evolution of the users’ privacy preferences as a result of on-going interactions. A prototype adaptive privacy management system was implemented based on this middleware; demonstrating the feasibility of adaptive privacy management for the target domain. Both the principles of adaptive privacy management and the prototype implementation were evaluated based on the results of a detailed user study using a GSM location sharing application constructed using the prototype platform. The study reveals the our core requirements are important for end users, and that our supporting design did provide adequate support for the characteristics we propose.