275 Chapter XIV Maintenance of Frequent Patterns: A Survey Mengling Feng Nanyang Technological University, Singapore Jinyan Li Nanyang Technological University, Singapore Guozhu Dong Wright State University, USA Limsoon Wong National University of Singapore, Singapore Copyright © 2009, IGI Global, distributing in print or electronic forms without written permission of IGI Global is prohibited. AbstrAct This chapter surveys the maintenance of frequent patterns in transaction datasets. It is written to be accessible to researchers familiar with the ield of frequent pattern mining. The frequent pattern main- tenance problem is summarized with a study on how the space of frequent patterns evolves in response to data updates. This chapter focuses on incremental and decremental maintenance. Four major types of maintenance algorithms are studied: Apriori-based, partition-based, preix-tree-based, and concise- representation-based algorithms. The authors study the advantages and limitations of these algorithms from both the theoretical and experimental perspectives. Possible solutions to certain limitations are also proposed. In addition, some potential research opportunities and emerging trends in frequent pat- tern maintenance are also discussed 1 .